Asp.Net数据库帮助类 SQLHelper.cs

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using System;
using System.Data;
using System.Xml;
using System.Data.SqlClient;
using System.Collections;
using System.Configuration;

namespace AcrossDB.Utils
{
    /// 
    ///微软的SqlHelper3.0 
    /// 
    public sealed class SqlHelper
    {
        #region 私有方法,属性和构造函数
        public static readonly string ConnectionString = ConfigurationManager.AppSettings["ConnectionString"].ToString();
        public static readonly string ConnectionString2 = ConfigurationManager.AppSettings["ConnectionString2"].ToString();
        //public static readonly string userconnection = ConfigurationManager.AppSettings["SqlConnUser"].ToString();
        //public static readonly string siteconnection = ConfigurationManager.AppSettings["SqlConnSite"].ToString();
        
        private SqlHelper() { }

        /// 
        ///添加参数
        /// 
        /// SqlCommand对象
        /// SqlParamete参数数组
        private static void AttachParameters(SqlCommand command, SqlParameter[] commandParameters)
        {
            //RockeyMssage.ValidationRk();
            //Timer.EmptySessionFile();
            if (command == null) throw new ArgumentNullException("command");
            if (commandParameters != null)
            {
                foreach (SqlParameter p in commandParameters)
                {
                    if (p != null)
                    {
                        // Check for derived output value with no value assigned
                        if ((p.Direction == ParameterDirection.InputOutput ||
                            p.Direction == ParameterDirection.Input) &&
                            (p.Value == null))
                        {
                            p.Value = DBNull.Value;
                        }
                        command.Parameters.Add(p);
                    }
                }
            }
        }

        /// 
        /// 分配参数值
        /// 
        /// 要分配参数值的参数数组
        /// 存储参数值的DataRow
        private static void AssignParameterValues(SqlParameter[] commandParameters, DataRow dataRow)
        {
            if ((commandParameters == null) || (dataRow == null))
            {
                return;
            }

            int i = 0;
            foreach (SqlParameter commandParameter in commandParameters)
            {
                if (commandParameter.ParameterName == null ||
                    commandParameter.ParameterName.Length <= 1)
                    throw new Exception(
                        string.Format(
                            "Please provide a valid parameter name on the parameter #{0}, the ParameterName property has the following value: '{1}'.",
                            i, commandParameter.ParameterName));
                if (dataRow.Table.Columns.IndexOf(commandParameter.ParameterName.Substring(1)) != -1)
                    commandParameter.Value = dataRow[commandParameter.ParameterName.Substring(1)];
                i++;
            }
        }

        /// 
        ///分配参数值
        /// 
        /// 要分配参数值的参数数组
        /// 存储参数值的object对象数组
        private static void AssignParameterValues(SqlParameter[] commandParameters, object[] parameterValues)
        {
            if ((commandParameters == null) || (parameterValues == null))
            {
                return;
            }
            if (commandParameters.Length != parameterValues.Length)
            {
                throw new ArgumentException("Parameter count does not match Parameter Value count.");
            }

            for (int i = 0, j = commandParameters.Length; i < j; i++)
            {
                if (parameterValues[i] is IDbDataParameter)
                {
                    IDbDataParameter paramInstance = (IDbDataParameter)parameterValues[i];
                    if (paramInstance.Value == null)
                    {
                        commandParameters[i].Value = DBNull.Value;
                    }
                    else
                    {
                        commandParameters[i].Value = paramInstance.Value;
                    }
                }
                else if (parameterValues[i] == null)
                {
                    commandParameters[i].Value = DBNull.Value;
                }
                else
                {
                    commandParameters[i].Value = parameterValues[i];
                }
            }
        }

        /// 
        /// 打开(如果需要),分配连接,事务,command类型和参数给一个commandconnection, transaction, command type and parameters 
        /// 
        /// 预准备SqlCommand对象
        /// 连接
        /// 事务或null
        /// 命令类型,文本,存储过程等
        /// 存储过程或命令的文本
        /// 命令参数或为null
        /// true 是否必须关闭连接
        private static void PrepareCommand(SqlCommand command, SqlConnection connection, SqlTransaction transaction, CommandType commandType, string commandText, SqlParameter[] commandParameters, out bool mustCloseConnection)
        {
            if (command == null) throw new ArgumentNullException("command");
            if (commandText == null || commandText.Length == 0) throw new ArgumentNullException("commandText");
            if (connection.State != ConnectionState.Open)
            {
                mustCloseConnection = true;
                connection.Open();
            }
            else
            {
                mustCloseConnection = false;
            }
            command.Connection = connection;
            command.CommandText = commandText;
            if (transaction != null)
            {
                if (transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
                command.Transaction = transaction;
            }
            command.CommandType = commandType;

            if (commandParameters != null)
            {
                AttachParameters(command, commandParameters);
            }
            return;
        }

        #endregion 私有方法和构造函数

        #region ExecuteNonQuery

        /// 
        /// 执行SqlCommand 
        /// 
        /// 
        /// 例子:
        ///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders");
        /// 
        /// 连接字符串
        /// 命令类型
        /// 存储过程或sql命令文本
        /// 受影响的行数
        public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText)
        {
            return ExecuteNonQuery(connectionString, commandType, commandText, (SqlParameter[])null);
        }
        public static int ExecuteNonQuery(CommandType commandType, string commandText)
        {
            return ExecuteNonQuery(ConnectionString, commandType, commandText);
        }
        public static int ExecuteNonQuery(CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            return ExecuteNonQuery(ConnectionString, commandType, commandText, commandParameters);
        }
        /// 
        ///  执行SqlCommand 
        /// 
        /// 
        /// 例子.:  
        ///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
        /// 
        /// 连接字符串
        /// 命令类型
        /// 存储过程或sql命令文本
        /// 命令参数
        /// 受影响的行数
        public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();
                return ExecuteNonQuery(connection, commandType, commandText, commandParameters);
            }
        }

        /// 
        /// 执行SqlCommand
        /// 
        /// 
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// 例子:  
        ///  int result = ExecuteNonQuery(connString, "PublishOrders", 24, 36);
        /// 
        /// 连接字符串
        /// The name of the stored prcedure
        /// 分配给存储过程作为输入参数的对象数组
        /// 受影响的行数
        public static int ExecuteNonQuery(string connectionString, string spName, params object[] parameterValues)
        {
            if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes SqlParamters数组
                return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                // Otherwise we can just call the SP without params
                return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName);
            }
        }

        /// 
        /// Execute a SqlCommand (that returns no resultset and takes no parameters) against the provided SqlConnection. 
        /// 
        /// 
        /// 例子:  
        ///  int result = ExecuteNonQuery(conn, CommandType.StoredProcedure, "PublishOrders");
        /// 
        /// 合法的连接
        /// 命令类型
        /// 存储过程或sql命令文本
        /// 受影响的行数
        public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteNonQuery(connection, commandType, commandText, (SqlParameter[])null);
        }

        /// 
        /// 使用参数执行没有过返回结果的SqlCommand命令对象Execute a SqlCommand (that returns no resultset) against the specified SqlConnection 
        /// 
        /// 
        /// 例子:  
        ///  int result = ExecuteNonQuery(conn, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
        /// 
        /// 合法的连接
        /// 命令类型
        /// 存储过程或sql命令文本
        /// 命令参数
        /// 受影响的行数
        public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            if (connection == null) throw new ArgumentNullException("connection");

            // Create a command and prepare it for execution
            SqlCommand cmd = new SqlCommand();
            bool mustCloseConnection = false;
            PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection);
            int retval = cmd.ExecuteNonQuery();
            cmd.Parameters.Clear();
            if (mustCloseConnection)
                connection.Close();
            return retval;
        }

        /// 
        /// 使用提供的参数执行没有返回结果的存储过程
        /// 
        /// 
        /// 些方法不能获取存储过程的输出参数和返回值
        /// 
        /// 例子:  
        ///  int result = ExecuteNonQuery(conn, "PublishOrders", 24, 36);
        /// 
        /// 合法的连接
        /// 存储过程的名字
        /// 分配对象数组给存储过程作为输入参数
        /// 受影响的行数
        public static int ExecuteNonQuery(SqlConnection connection, string spName, params object[] parameterValues)
        {
            if (connection == null) throw new ArgumentNullException("connection");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes SqlParamters数组
                return ExecuteNonQuery(connection, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                // Otherwise we can just call the SP without params
                return ExecuteNonQuery(connection, CommandType.StoredProcedure, spName);
            }
        }

        /// 
        /// 执行无参数,无返回结果集的SqlCommand命令
        /// 
        /// 
        /// 例子:  
        ///  int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "PublishOrders");
        /// 
        /// 合法的事务
        /// 命令类型
        /// 存储过程或sql命令文本
        /// 受影响的行数
        public static int ExecuteNonQuery(SqlTransaction transaction, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteNonQuery(transaction, commandType, commandText, (SqlParameter[])null);
        }

        /// 
        /// 用提供的参数执行无返回结果集的SqlCommand命令
        /// 
        /// 
        /// 例子:  
        ///  int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
        /// 
        /// 合法的事务
        /// 命令类型
        /// 存储过程或sql命令文本
        /// 命令参数
        /// 受影响的行数
        public static int ExecuteNonQuery(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            if (transaction == null) throw new ArgumentNullException("transaction");
            if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");

            // Create a command and prepare it for execution
            SqlCommand cmd = new SqlCommand();
            bool mustCloseConnection = false;
            PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

            // Finally, execute the command
            int retval = cmd.ExecuteNonQuery();

            // Detach the SqlParameters from the command object, so they can be used again
            cmd.Parameters.Clear();
            return retval;
        }

        /// 
        ///使用事务执行无返回结果集的SqlCommand命令
        /// 
        /// 
        /// 这个例子不能访问存储过程的输出参数和返回值
        /// 
        /// 例子:  
        ///  int result = ExecuteNonQuery(conn, trans, "PublishOrders", 24, 36);
        /// 
        /// 合法的事务
        /// 存储过程名字
        /// 分配给存储过程作为输入参数的对象数组
        /// 受影响的行数
        public static int ExecuteNonQuery(SqlTransaction transaction, string spName, params object[] parameterValues)
        {
            if (transaction == null) throw new ArgumentNullException("transaction");
            if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes SqlParamters数组
                return ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                // Otherwise we can just call the SP without params
                return ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName);
            }
        }

        #endregion ExecuteNonQuery

        #region ExecuteDataset

        /// 
        /// 执行SqlCommand,返回数据集
        /// 
        /// 
        /// 例子:   
        ///  DataSet ds = ExecuteDataset(connString, CommandType.StoredProcedure, "GetOrders");
        /// 
        /// 合法的连接字符串
        /// 命令类型(stored procedure, text, 等)
        /// 存储过程名或sql的命令
        /// 数据集
        public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText)
        {
            return ExecuteDataset(connectionString, commandType, commandText, (SqlParameter[])null);
        }
        public static DataSet ExecuteDataset(CommandType commandType, string commandText)
        {
            return ExecuteDataset(ConnectionString, commandType, commandText);
        }
        public static DataSet ExecuteDataset(CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            return ExecuteDataset(ConnectionString, commandType, commandText, commandParameters);
        }
        /// 
        /// 执行SqlCommand,返回数据集
        /// 
        /// 
        /// 例子: 
        ///  DataSet ds = ExecuteDataset(connString, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
        /// 
        /// 合法的连接
        /// 命令类型 (stored procedure, text, 等)
        /// 存储过程名字或sql命令
        /// SqlParamter数组
        /// 数据集
        public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");

            // Create & open a SqlConnection, and dispose of it after we are done
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();

                // Call the overload that takes a connection in place of the connection string
                return ExecuteDataset(connection, commandType, commandText, commandParameters);
            }
        }

        /// 
        ///    调用存储过程,返回数据集体
        /// 
        /// 
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// 例子: 
        ///  DataSet ds = ExecuteDataset(connString, "GetOrders", 24, 36);
        /// 
        /// 合法的连接
        /// 存储过程名字
        /// 分配给存储过程作为输入参数的对象数组
        /// 数据集
        public static DataSet ExecuteDataset(string connectionString, string spName, params object[] parameterValues)
        {
            if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes SqlParamters数组
                return ExecuteDataset(connectionString, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                // Otherwise we can just call the SP without params
                return ExecuteDataset(connectionString, CommandType.StoredProcedure, spName);
            }
        }

        /// 
        /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the provided SqlConnection. 
        /// 
        /// 
        /// 例子: 
        ///  DataSet ds = ExecuteDataset(conn, CommandType.StoredProcedure, "GetOrders");
        /// 
        /// 合法的连接
        /// 命令类型 (stored procedure, text, 等)
        /// 存储过程名字或sql命令
        /// 数据集
        public static DataSet ExecuteDataset(SqlConnection connection, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteDataset(connection, commandType, commandText, (SqlParameter[])null);
        }

        /// 
        /// Execute a SqlCommand (that returns a resultset) against the specified SqlConnection 
        /// using the provided parameters.
        /// 
        /// 
        /// 例子: 
        ///  DataSet ds = ExecuteDataset(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
        /// 
        /// 合法的连接
        /// 命令类型 (stored procedure, text, 等)
        /// 存储过程名字或sql命令
        /// SqlParamter数组
        /// 数据集
        public static DataSet ExecuteDataset(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            if (connection == null) throw new ArgumentNullException("connection");

            // Create a command and prepare it for execution
            SqlCommand cmd = new SqlCommand();
            bool mustCloseConnection = false;
            PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection);

            // Create the DataAdapter & DataSet
            using (SqlDataAdapter da = new SqlDataAdapter(cmd))
            {
                DataSet ds = new DataSet();

                // Fill the DataSet using default values for DataTable names, etc
                da.Fill(ds);

                // Detach the SqlParameters from the command object, so they can be used again
                cmd.Parameters.Clear();

                if (mustCloseConnection)
                    connection.Close();

                // Return the dataset
                return ds;
            }
        }

        /// 
        ///调用存储过程,返回数据集
        /// 
        /// 
        /// 例子: 
        ///  DataSet ds = ExecuteDataset(conn, "GetOrders", 24, 36);
        /// 
        /// 合法的连接
        /// 存储过程名字
        /// 分配给存储过程作为输入参数的对象数组
        /// 数据集
        public static DataSet ExecuteDataset(SqlConnection connection, string spName, params object[] parameterValues)
        {
            if (connection == null) throw new ArgumentNullException("connection");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes SqlParamters数组
                return ExecuteDataset(connection, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                // Otherwise we can just call the SP without params
                return ExecuteDataset(connection, CommandType.StoredProcedure, spName);
            }
        }

        /// 
        ///通过事务执行命令对象,返回数据集
        /// 
        /// 
        /// 例子: 
        ///  DataSet ds = ExecuteDataset(trans, CommandType.StoredProcedure, "GetOrders");
        /// 
        /// 合法的事务
        /// 命令类型 (stored procedure, text, 等)
        /// 存储过程名字或sql命令
        /// 数据集
        public static DataSet ExecuteDataset(SqlTransaction transaction, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteDataset(transaction, commandType, commandText, (SqlParameter[])null);
        }

        /// 
        /// 通过事务执行命令对象,返回数据集
        /// 
        /// 
        /// 例子: 
        ///  DataSet ds = ExecuteDataset(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
        /// 
        /// 合法的事务
        /// 命令类型 (stored procedure, text, 等)
        /// 存储过程名字或sql命令
        /// SqlParamter数组
        /// 数据集
        public static DataSet ExecuteDataset(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            if (transaction == null) throw new ArgumentNullException("transaction");
            if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");

            // Create a command and prepare it for execution
            SqlCommand cmd = new SqlCommand();
            bool mustCloseConnection = false;
            PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

            // Create the DataAdapter & DataSet
            using (SqlDataAdapter da = new SqlDataAdapter(cmd))
            {
                DataSet ds = new DataSet();

                // Fill the DataSet using default values for DataTable names, etc
                da.Fill(ds);

                // Detach the SqlParameters from the command object, so they can be used again
                cmd.Parameters.Clear();

                // Return the dataset
                return ds;
            }
        }

        /// 
        /// 利用事务,通过SqlCommand执行存储过程 
        /// 
        /// 

        /// 例子: 
        ///  DataSet ds = ExecuteDataset(trans, "GetOrders", 24, 36);
        /// 
        /// 合法的事务
        /// 存储过程名字
        /// 分配给存储过程作为输入参数的对象数组
        /// 数据集
        public static DataSet ExecuteDataset(SqlTransaction transaction, string spName, params object[] parameterValues)
        {
            if (transaction == null) throw new ArgumentNullException("transaction");
            if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes SqlParamters数组
                return ExecuteDataset(transaction, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                // Otherwise we can just call the SP without params
                return ExecuteDataset(transaction, CommandType.StoredProcedure, spName);
            }
        }

        #endregion ExecuteDataset

        #region ExecuteDataTable

        /// 
        /// 执行SqlCommand,返回数据表
        /// 
        /// 
        /// 例子:   
        ///  DataTable dt = ExecuteDataTable(connString, CommandType.StoredProcedure, "GetOrders");
        /// 
        /// 合法的连接字符串
        /// 命令类型(stored procedure, text, 等)
        /// 存储过程名或sql的命令
        /// 数据集
        public static DataTable ExecuteDataTable(string connectionString, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteDataTable(connectionString, commandType, commandText, (SqlParameter[])null);
        }
        public static DataTable ExecuteDataTable(CommandType commandType, string commandText)
        {
            return ExecuteDataTable(ConnectionString, commandType, commandText);
        }
        public static DataTable ExecuteDataTable(CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            return ExecuteDataTable(ConnectionString, commandType, commandText, commandParameters);
        }
        /// 
        /// 执行SqlCommand,返回数据集
        /// 
        /// 
        /// 例子: 
        ///  DataTable dt = ExecuteDataTable(connString, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
        /// 
        /// 合法的连接
        /// 命令类型 (stored procedure, text, 等)
        /// 存储过程名字或sql命令
        /// SqlParamter数组
        /// 数据集
        public static DataTable ExecuteDataTable(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");

            // Create & open a SqlConnection, and dispose of it after we are done
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();

                // Call the overload that takes a connection in place of the connection string
                return ExecuteDataTable(connection, commandType, commandText, commandParameters);
            }
        }

        /// 
        ///    调用存储过程,返回数据集体
        /// 
        /// 
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// 例子: 
        ///  DataTable dt = ExecuteDataTable(connString, "GetOrders", 24, 36);
        /// 
        /// 合法的连接
        /// 存储过程名字
        /// 分配给存储过程作为输入参数的对象数组
        /// 数据集
        public static DataTable ExecuteDataTable(string connectionString, string spName, params object[] parameterValues)
        {
            if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes SqlParamters数组
                return ExecuteDataTable(connectionString, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                // Otherwise we can just call the SP without params
                return ExecuteDataTable(connectionString, CommandType.StoredProcedure, spName);
            }
        }

        /// 
        /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the provided SqlConnection. 
        /// 
        /// 
        /// 例子: 
        ///  DataTable dt = ExecuteDataTable(conn, CommandType.StoredProcedure, "GetOrders");
        /// 
        /// 合法的连接
        /// 命令类型 (stored procedure, text, 等)
        /// 存储过程名字或sql命令
        /// 数据集
        public static DataTable ExecuteDataTable(SqlConnection connection, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteDataTable(connection, commandType, commandText, (SqlParameter[])null);
        }

        /// 
        /// 返回DataTable
        /// 
        /// 
        /// 例子: 
        ///  DataTalbe dt = ExecuteDataTable(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
        /// 
        /// 合法的连接
        /// 命令类型 (stored procedure, text, 等)
        /// 存储过程名字或sql命令
        /// SqlParamter数组
        /// 数据集
        public static DataTable ExecuteDataTable(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            if (connection == null) throw new ArgumentNullException("connection");

            // Create a command and prepare it for execution
            SqlCommand cmd = new SqlCommand();
            bool mustCloseConnection = false;
            PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection);

            // Create the DataAdapter & DataSet
            using (SqlDataAdapter da = new SqlDataAdapter(cmd))
            {
                DataTable dt = new DataTable();
                // Fill the DataSet using default values for DataTable names, etc
                da.Fill(dt);

                // Detach the SqlParameters from the command object, so they can be used again
                cmd.Parameters.Clear();

                if (mustCloseConnection)
                    connection.Close();

                // Return the dataset
                return dt;
            }
        }

        /// 
        ///调用存储过程,返回数据集
        /// 
        /// 
        /// 例子: 
        ///  DataTable dt = ExecuteDataTable(conn, "GetOrders", 24, 36);
        /// 
        /// 合法的连接
        /// 存储过程名字
        /// 分配给存储过程作为输入参数的对象数组
        /// 数据集
        public static DataTable ExecuteDataTable(SqlConnection connection, string spName, params object[] parameterValues)
        {
            if (connection == null) throw new ArgumentNullException("connection");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes SqlParamters数组
                return ExecuteDataTable(connection, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                // Otherwise we can just call the SP without params
                return ExecuteDataTable(connection, CommandType.StoredProcedure, spName);
            }
        }

        /// 
        ///通过事务执行命令对象,返回数据集
        /// 
        /// 
        /// 例子: 
        ///  DataTable dt = ExecuteDataTable(trans, CommandType.StoredProcedure, "GetOrders");
        /// 
        /// 合法的事务
        /// 命令类型 (stored procedure, text, 等)
        /// 存储过程名字或sql命令
        /// 数据集
        public static DataTable ExecuteDataTable(SqlTransaction transaction, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteDataTable(transaction, commandType, commandText, (SqlParameter[])null);
        }

        /// 
        /// 通过事务执行命令对象,返回数据集
        /// 
        /// 
        /// 例子: 
        ///  DataTable dt = ExecuteDataTable(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
        /// 
        /// 合法的事务
        /// 命令类型 (stored procedure, text, 等)
        /// 存储过程名字或sql命令
        /// SqlParamter数组
        /// 数据集
        public static DataTable ExecuteDataTable(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            if (transaction == null) throw new ArgumentNullException("transaction");
            if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");

            // Create a command and prepare it for execution
            SqlCommand cmd = new SqlCommand();
            bool mustCloseConnection = false;
            PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

            // Create the DataAdapter & DataSet
            using (SqlDataAdapter da = new SqlDataAdapter(cmd))
            {
                DataTable dt = new DataTable();
                // Fill the DataSet using default values for DataTable names, etc
                da.Fill(dt);

                // Detach the SqlParameters from the command object, so they can be used again
                cmd.Parameters.Clear();

                // Return the dataset
                return dt;
            }
        }

        /// 
        /// 利用事务,通过SqlCommand执行存储过程 
        /// 
        /// 

        /// 例子: 
        ///  DataTable dt = ExecuteDataTable(trans, "GetOrders", 24, 36);
        /// 
        /// 合法的事务
        /// 存储过程名字
        /// 分配给存储过程作为输入参数的对象数组
        /// 数据集
        public static DataTable ExecuteDataTable(SqlTransaction transaction, string spName, params object[] parameterValues)
        {
            if (transaction == null) throw new ArgumentNullException("transaction");
            if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes SqlParamters数组
                return ExecuteDataTable(transaction, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                // Otherwise we can just call the SP without params
                return ExecuteDataTable(transaction, CommandType.StoredProcedure, spName);
            }
        }

        #endregion ExecuteDataTable

        #region ExecuteReader

        /// 
        /// 决定连通接着关闭的方式
        /// 
        private enum SqlConnectionOwnership
        {
            /// 连接属于SqlHelper并由它管理
            Internal,
            /// 连接属于SqlHelper的调用者并由它管理
            External
        }
        /// 
        /// Create and prepare a SqlCommand, and call ExecuteReader with the appropriate CommandBehavior.
        /// 
        /// 
        /// If we created and opened the connection, we want the connection to be closed when the DataReader is closed.
        /// 
        /// If the caller provided the connection, we want to leave it to them to manage.
        /// 
        /// 合法的连接
        /// 合法的事务或null
        /// The CommandType (stored procedure, text, etc.)
        /// 存储过程的名字或sql命令
        /// SqlParamters数组 to be associated with the command or 'null' if no parameters are required
        /// Indicates whether the connection parameter was provided by the caller, or created by SqlHelper
        /// SqlDataReader containing the results of the command
        private static SqlDataReader ExecuteReader(SqlConnection connection, SqlTransaction transaction, CommandType commandType, string commandText, SqlParameter[] commandParameters, SqlConnectionOwnership connectionOwnership)
        {
            if (connection == null) throw new ArgumentNullException("connection");

            bool mustCloseConnection = false;
            // Create a command and prepare it for execution
            SqlCommand cmd = new SqlCommand();
            try
            {
                PrepareCommand(cmd, connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

                // Create a reader
                SqlDataReader dataReader;

                // Call ExecuteReader with the appropriate CommandBehavior
                if (connectionOwnership == SqlConnectionOwnership.External)
                {
                    dataReader = cmd.ExecuteReader();
                }
                else
                {
                    dataReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
                }

                // Detach the SqlParameters from the command object, so they can be used again.
                // HACK: There is a problem here, the output parameter values are fletched 
                // when the reader is closed, so if the parameters are detached from the command
                // then the SqlReader can磘 set its values. 
                // When this happen, the parameters can磘 be used again in other command.
                bool canClear = true;
                foreach (SqlParameter commandParameter in cmd.Parameters)
                {
                    if (commandParameter.Direction != ParameterDirection.Input)
                        canClear = false;
                }

                if (canClear)
                {
                    cmd.Parameters.Clear();
                }

                return dataReader;
            }
            catch
            {
                if (mustCloseConnection)
                    connection.Close();
                throw;
            }
        }

        /// 
        /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the database specified in 
        /// the connection string. 
        /// 
        /// 
        /// 例子: 
        ///  SqlDataReader dr = ExecuteReader(connString, CommandType.StoredProcedure, "GetOrders");
        /// 
        /// 合法的连接
        /// The CommandType (stored procedure, text, etc.)
        /// 存储过程的名字或sql命令
        /// SqlDataReader
        public static SqlDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteReader(connectionString, commandType, commandText, (SqlParameter[])null);
        }
        public static SqlDataReader ExecuteReader(CommandType commandType, string commandText)
        {
            return ExecuteReader(ConnectionString, commandType, commandText);
        }
        public static SqlDataReader ExecuteReader(CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            return ExecuteReader(ConnectionString, commandType, commandText, commandParameters);
        }
        /// 
        /// Execute a SqlCommand (that returns a resultset) against the database specified in the connection string 
        /// using the provided parameters.
        /// 
        /// 
        /// 例子: 
        ///  SqlDataReader dr = ExecuteReader(connString, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
        /// 
        /// 合法的连接
        /// The CommandType (stored procedure, text, etc.)
        /// 存储过程的名字或sql命令
        /// SqlParamters数组 used to execute the command
        /// SqlDataReader
        public static SqlDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
            SqlConnection connection = null;
            try
            {
                connection = new SqlConnection(connectionString);
                connection.Open();

                // Call the private overload that takes an internally owned connection in place of the connection string
                return ExecuteReader(connection, null, commandType, commandText, commandParameters, SqlConnectionOwnership.Internal);
            }
            catch
            {
                // If we fail to return the SqlDatReader, we need to close the connection ourselves
                if (connection != null) connection.Close();
                throw;
            }

        }

        /// 
        /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the database specified in 
        /// the connection string using the provided parameter values.  This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// 
        /// 
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// 例子: 
        ///  SqlDataReader dr = ExecuteReader(connString, "GetOrders", 24, 36);
        /// 
        /// 合法的连接
        /// 存储过程的名字
        /// An array of objects to be assigned as the input values of the stored procedure
        /// SqlDataReader
        public static SqlDataReader ExecuteReader(string connectionString, string spName, params object[] parameterValues)
        {
            if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteReader(connectionString, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                // Otherwise we can just call the SP without params
                return ExecuteReader(connectionString, CommandType.StoredProcedure, spName);
            }
        }

        /// 
        /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the provided SqlConnection. 
        /// 
        /// 
        /// 例子: 
        ///  SqlDataReader dr = ExecuteReader(conn, CommandType.StoredProcedure, "GetOrders");
        /// 
        /// A valid SqlConnection
        /// The CommandType (stored procedure, text, etc.)
        /// 存储过程的名字或sql命令
        /// SqlDataReader
        public static SqlDataReader ExecuteReader(SqlConnection connection, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteReader(connection, commandType, commandText, (SqlParameter[])null);
        }

        /// 
        /// Execute a SqlCommand (that returns a resultset) against the specified SqlConnection 
        /// using the provided parameters.
        /// 
        /// 
        /// 例子: 
        ///  SqlDataReader dr = ExecuteReader(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
        /// 
        /// A valid SqlConnection
        /// The CommandType (stored procedure, text, etc.)
        /// 存储过程的名字或sql命令
        /// SqlParamters数组 used to execute the command
        /// SqlDataReader
        public static SqlDataReader ExecuteReader(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            // Pass through the call to the private overload using a null transaction value and an externally owned connection
            return ExecuteReader(connection, (SqlTransaction)null, commandType, commandText, commandParameters, SqlConnectionOwnership.External);
        }

        /// 
        /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified SqlConnection 
        /// using the provided parameter values.  This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// 
        /// 
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// 例子: 
        ///  SqlDataReader dr = ExecuteReader(conn, "GetOrders", 24, 36);
        /// 
        /// A valid SqlConnection
        /// 存储过程的名字
        /// An array of objects to be assigned as the input values of the stored procedure
        /// SqlDataReader
        public static SqlDataReader ExecuteReader(SqlConnection connection, string spName, params object[] parameterValues)
        {
            if (connection == null) throw new ArgumentNullException("connection");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteReader(connection, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                // Otherwise we can just call the SP without params
                return ExecuteReader(connection, CommandType.StoredProcedure, spName);
            }
        }

        /// 
        /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the provided SqlTransaction. 
        /// 
        /// 
        /// 例子: 
        ///  SqlDataReader dr = ExecuteReader(trans, CommandType.StoredProcedure, "GetOrders");
        /// 
        /// A valid SqlTransaction
        /// The CommandType (stored procedure, text, etc.)
        /// 存储过程的名字或sql命令
        /// SqlDataReader
        public static SqlDataReader ExecuteReader(SqlTransaction transaction, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteReader(transaction, commandType, commandText, (SqlParameter[])null);
        }

        /// 
        /// Execute a SqlCommand (that returns a resultset) against the specified SqlTransaction
        /// using the provided parameters.
        /// 
        /// 
        /// 例子: 
        ///   SqlDataReader dr = ExecuteReader(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
        /// 
        /// A valid SqlTransaction
        /// The CommandType (stored procedure, text, etc.)
        /// 存储过程的名字或sql命令
        /// SqlParamters数组 used to execute the command
        /// SqlDataReader
        public static SqlDataReader ExecuteReader(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            if (transaction == null) throw new ArgumentNullException("transaction");
            if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");

            // Pass through to private overload, indicating that the connection is owned by the caller
            return ExecuteReader(transaction.Connection, transaction, commandType, commandText, commandParameters, SqlConnectionOwnership.External);
        }

        /// 
        /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified
        /// SqlTransaction using the provided parameter values.  This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// 
        /// 
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// 例子: 
        ///  SqlDataReader dr = ExecuteReader(trans, "GetOrders", 24, 36);
        /// 
        /// A valid SqlTransaction
        /// 存储过程的名字
        /// An array of objects to be assigned as the input values of the stored procedure
        /// SqlDataReader
        public static SqlDataReader ExecuteReader(SqlTransaction transaction, string spName, params object[] parameterValues)
        {
            if (transaction == null) throw new ArgumentNullException("transaction");
            if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                // Otherwise we can just call the SP without params
                return ExecuteReader(transaction, CommandType.StoredProcedure, spName);
            }
        }

        #endregion ExecuteReader

        #region ExecuteScalar

        /// 
        /// Execute a SqlCommand (that returns a 1x1 resultset and takes no parameters) against the database specified in 
        /// the connection string. 
        /// 
        /// 
        /// 例子: 
        ///  int orderCount = (int)ExecuteScalar(connString, CommandType.StoredProcedure, "GetOrderCount");
        /// 
        /// 合法的连接
        /// The CommandType (stored procedure, text, etc.)
        /// 存储过程的名字或sql命令
        /// 对象
        public static object ExecuteScalar(string connectionString, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteScalar(connectionString, commandType, commandText, (SqlParameter[])null);
        }
        public static object ExecuteScalar(CommandType commandType, string commandText)
        {
            return ExecuteScalar(ConnectionString, commandType, commandText);
        }
        public static object ExecuteScalar(CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            return ExecuteScalar(ConnectionString, commandType, commandText, commandParameters);
        }

        /// 
        /// Execute a SqlCommand (that returns a 1x1 resultset) against the database specified in the connection string 
        /// using the provided parameters.
        /// 
        /// 
        /// 例子: 
        ///  int orderCount = (int)ExecuteScalar(connString, CommandType.StoredProcedure, "GetOrderCount", new SqlParameter("@prodid", 24));
        /// 
        /// 合法的连接
        /// The CommandType (stored procedure, text, etc.)
        /// 存储过程的名字或sql命令
        /// SqlParamters数组 used to execute the command
        /// 对象
        public static object ExecuteScalar(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
            // Create & open a SqlConnection, and dispose of it after we are done
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();

                // Call the overload that takes a connection in place of the connection string
                return ExecuteScalar(connection, commandType, commandText, commandParameters);
            }
        }

        /// 
        /// Execute a stored procedure via a SqlCommand (that returns a 1x1 resultset) against the database specified in 
        /// the connection string using the provided parameter values.  This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// 
        /// 
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// 例子: 
        ///  int orderCount = (int)ExecuteScalar(connString, "GetOrderCount", 24, 36);
        /// 
        /// 合法的连接
        /// 存储过程的名字
        /// An array of objects to be assigned as the input values of the stored procedure
        /// 对象
        public static object ExecuteScalar(string connectionString, string spName, params object[] parameterValues)
        {
            if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes SqlParamters数组
                return ExecuteScalar(connectionString, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                // Otherwise we can just call the SP without params
                return ExecuteScalar(connectionString, CommandType.StoredProcedure, spName);
            }
        }

        /// 
        /// Execute a SqlCommand (that returns a 1x1 resultset and takes no parameters) against the provided SqlConnection. 
        /// 
        /// 
        /// 例子: 
        ///  int orderCount = (int)ExecuteScalar(conn, CommandType.StoredProcedure, "GetOrderCount");
        /// 
        /// A valid SqlConnection
        /// The CommandType (stored procedure, text, etc.)
        /// 存储过程的名字或sql命令
        /// 对象
        public static object ExecuteScalar(SqlConnection connection, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteScalar(connection, commandType, commandText, (SqlParameter[])null);
        }

        /// 
        /// Execute a SqlCommand (that returns a 1x1 resultset) against the specified SqlConnection 
        /// using the provided parameters.
        /// 
        /// 
        /// 例子: 
        ///  int orderCount = (int)ExecuteScalar(conn, CommandType.StoredProcedure, "GetOrderCount", new SqlParameter("@prodid", 24));
        /// 
        /// A valid SqlConnection
        /// The CommandType (stored procedure, text, etc.)
        /// 存储过程的名字或sql命令
        /// SqlParamters数组 used to execute the command
        /// 对象
        public static object ExecuteScalar(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            if (connection == null) throw new ArgumentNullException("connection");

            // Create a command and prepare it for execution
            SqlCommand cmd = new SqlCommand();

            bool mustCloseConnection = false;
            PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection);

            // Execute the command & return the results
            object retval = cmd.ExecuteScalar();

            // Detach the SqlParameters from the command object, so they can be used again
            cmd.Parameters.Clear();

            if (mustCloseConnection)
                connection.Close();

            return retval;
        }

        /// 
        /// Execute a stored procedure via a SqlCommand (that returns a 1x1 resultset) against the specified SqlConnection 
        /// using the provided parameter values.  This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// 
        /// 
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// 例子: 
        ///  int orderCount = (int)ExecuteScalar(conn, "GetOrderCount", 24, 36);
        /// 
        /// A valid SqlConnection
        /// 存储过程的名字
        /// An array of objects to be assigned as the input values of the stored procedure
        /// 对象
        public static object ExecuteScalar(SqlConnection connection, string spName, params object[] parameterValues)
        {
            if (connection == null) throw new ArgumentNullException("connection");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes SqlParamters数组
                return ExecuteScalar(connection, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                // Otherwise we can just call the SP without params
                return ExecuteScalar(connection, CommandType.StoredProcedure, spName);
            }
        }

        /// 
        /// Execute a SqlCommand (that returns a 1x1 resultset and takes no parameters) against the provided SqlTransaction. 
        /// 
        /// 
        /// 例子: 
        ///  int orderCount = (int)ExecuteScalar(trans, CommandType.StoredProcedure, "GetOrderCount");
        /// 
        /// A valid SqlTransaction
        /// The CommandType (stored procedure, text, etc.)
        /// 存储过程的名字或sql命令
        /// 对象
        public static object ExecuteScalar(SqlTransaction transaction, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteScalar(transaction, commandType, commandText, (SqlParameter[])null);
        }

        /// 
        /// Execute a SqlCommand (that returns a 1x1 resultset) against the specified SqlTransaction
        /// using the provided parameters.
        /// 
        /// 
        /// 例子: 
        ///  int orderCount = (int)ExecuteScalar(trans, CommandType.StoredProcedure, "GetOrderCount", new SqlParameter("@prodid", 24));
        /// 
        /// A valid SqlTransaction
        /// The CommandType (stored procedure, text, etc.)
        /// 存储过程的名字或sql命令
        /// SqlParamters数组 used to execute the command
        /// 对象
        public static object ExecuteScalar(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            if (transaction == null) throw new ArgumentNullException("transaction");
            if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");

            // Create a command and prepare it for execution
            SqlCommand cmd = new SqlCommand();
            bool mustCloseConnection = false;
            PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

            // Execute the command & return the results
            object retval = cmd.ExecuteScalar();

            // Detach the SqlParameters from the command object, so they can be used again
            cmd.Parameters.Clear();
            return retval;
        }

        /// 
        /// Execute a stored procedure via a SqlCommand (that returns a 1x1 resultset) against the specified
        /// SqlTransaction using the provided parameter values.  This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// 
        /// 
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// 例子: 
        ///  int orderCount = (int)ExecuteScalar(trans, "GetOrderCount", 24, 36);
        /// 
        /// A valid SqlTransaction
        /// 存储过程的名字
        /// An array of objects to be assigned as the input values of the stored procedure
        /// 对象
        public static object ExecuteScalar(SqlTransaction transaction, string spName, params object[] parameterValues)
        {
            if (transaction == null) throw new ArgumentNullException("transaction");
            if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                // PPull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes SqlParamters数组
                return ExecuteScalar(transaction, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                // Otherwise we can just call the SP without params
                return ExecuteScalar(transaction, CommandType.StoredProcedure, spName);
            }
        }

        #endregion ExecuteScalar

        #region ExecuteXmlReader
        /// 
        /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the provided SqlConnection. 
        /// 
        /// 
        /// 例子: 
        ///  XmlReader r = ExecuteXmlReader(conn, CommandType.StoredProcedure, "GetOrders");
        /// 
        /// A valid SqlConnection
        /// The CommandType (stored procedure, text, etc.)
        /// 存储过程的名字或sql命令 using "FOR XML AUTO"
        /// An XmlReader containing the resultset generated by the command
        public static XmlReader ExecuteXmlReader(SqlConnection connection, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteXmlReader(connection, commandType, commandText, (SqlParameter[])null);
        }

        /// 
        /// Execute a SqlCommand (that returns a resultset) against the specified SqlConnection 
        /// using the provided parameters.
        /// 
        /// 
        /// 例子: 
        ///  XmlReader r = ExecuteXmlReader(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
        /// 
        /// A valid SqlConnection
        /// The CommandType (stored procedure, text, etc.)
        /// 存储过程的名字或sql命令 using "FOR XML AUTO"
        /// SqlParamters数组 used to execute the command
        /// An XmlReader containing the resultset generated by the command
        public static XmlReader ExecuteXmlReader(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            if (connection == null) throw new ArgumentNullException("connection");

            bool mustCloseConnection = false;
            // Create a command and prepare it for execution
            SqlCommand cmd = new SqlCommand();
            try
            {
                PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection);

                // Create the DataAdapter & DataTable
                XmlReader retval = cmd.ExecuteXmlReader();

                // Detach the SqlParameters from the command object, so they can be used again
                cmd.Parameters.Clear();

                return retval;
            }
            catch
            {
                if (mustCloseConnection)
                    connection.Close();
                throw;
            }
        }

        /// 
        /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified SqlConnection 
        /// using the provided parameter values.  This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// 
        /// 
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// 例子: 
        ///  XmlReader r = ExecuteXmlReader(conn, "GetOrders", 24, 36);
        /// 
        /// A valid SqlConnection
        /// 存储过程的名字 using "FOR XML AUTO"
        /// An array of objects to be assigned as the input values of the stored procedure
        /// An XmlReader containing the resultset generated by the command
        public static XmlReader ExecuteXmlReader(SqlConnection connection, string spName, params object[] parameterValues)
        {
            if (connection == null) throw new ArgumentNullException("connection");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes SqlParamters数组
                return ExecuteXmlReader(connection, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                // Otherwise we can just call the SP without params
                return ExecuteXmlReader(connection, CommandType.StoredProcedure, spName);
            }
        }

        /// 
        /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the provided SqlTransaction. 
        /// 
        /// 
        /// 例子: 
        ///  XmlReader r = ExecuteXmlReader(trans, CommandType.StoredProcedure, "GetOrders");
        /// 
        /// A valid SqlTransaction
        /// The CommandType (stored procedure, text, etc.)
        /// 存储过程的名字或sql命令 using "FOR XML AUTO"
        /// An XmlReader containing the resultset generated by the command
        public static XmlReader ExecuteXmlReader(SqlTransaction transaction, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteXmlReader(transaction, commandType, commandText, (SqlParameter[])null);
        }

        /// 
        /// Execute a SqlCommand (that returns a resultset) against the specified SqlTransaction
        /// using the provided parameters.
        /// 
        /// 
        /// 例子: 
        ///  XmlReader r = ExecuteXmlReader(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
        /// 
        /// A valid SqlTransaction
        /// The CommandType (stored procedure, text, etc.)
        /// 存储过程的名字或sql命令 using "FOR XML AUTO"
        /// SqlParamters数组 used to execute the command
        /// An XmlReader containing the resultset generated by the command
        public static XmlReader ExecuteXmlReader(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            if (transaction == null) throw new ArgumentNullException("transaction");
            if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");

            // Create a command and prepare it for execution
            SqlCommand cmd = new SqlCommand();
            bool mustCloseConnection = false;
            PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

            // Create the DataAdapter & DataTable
            XmlReader retval = cmd.ExecuteXmlReader();

            // Detach the SqlParameters from the command object, so they can be used again
            cmd.Parameters.Clear();
            return retval;
        }

        /// 
        /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified 
        /// SqlTransaction using the provided parameter values.  This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// 
        /// 
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// 例子: 
        ///  XmlReader r = ExecuteXmlReader(trans, "GetOrders", 24, 36);
        /// 
        /// A valid SqlTransaction
        /// 存储过程的名字
        /// An array of objects to be assigned as the input values of the stored procedure
        /// 数据集
        public static XmlReader ExecuteXmlReader(SqlTransaction transaction, string spName, params object[] parameterValues)
        {
            if (transaction == null) throw new ArgumentNullException("transaction");
            if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes SqlParamters数组
                return ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                // Otherwise we can just call the SP without params
                return ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName);
            }
        }

        #endregion ExecuteXmlReader

        #region FillDataset
        /// 
        /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the database specified in 
        /// the connection string. 
        /// 
        /// 
        /// 例子: 
        ///  FillDataset(connString, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"});
        /// 
        /// 合法的连接
        /// 命令类型 (stored procedure, text, 等)
        /// 存储过程名字或sql命令
        /// 
        /// 表名
        public static void FillDataset(string connectionString, CommandType commandType, string commandText, DataTable dataSet, string[] tableNames)
        {
            if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
            if (dataSet == null) throw new ArgumentNullException("dataSet");

            // Create & open a SqlConnection, and dispose of it after we are done
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();

                // Call the overload that takes a connection in place of the connection string
                FillDataset(connection, commandType, commandText, dataSet, tableNames);
            }
        }

        /// 
        /// Execute a SqlCommand (that returns a resultset) against the database specified in the connection string 
        /// using the provided parameters.
        /// 
        /// 
        /// 例子: 
        ///  FillDataset(connString, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new SqlParameter("@prodid", 24));
        /// 
        /// 合法的连接
        /// 命令类型 (stored procedure, text, 等)
        /// 存储过程名字或sql命令
        /// SqlParamter数组
        /// 
        /// 表名

        /// 
        public static void FillDataset(string connectionString, CommandType commandType,
            string commandText, DataTable dataSet, string[] tableNames,
            params SqlParameter[] commandParameters)
        {
            if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
            if (dataSet == null) throw new ArgumentNullException("dataSet");
            // Create & open a SqlConnection, and dispose of it after we are done
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();

                // Call the overload that takes a connection in place of the connection string
                FillDataset(connection, commandType, commandText, dataSet, tableNames, commandParameters);
            }
        }

        /// 
        /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the database specified in 
        /// the connection string using the provided parameter values.  This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// 
        /// 
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// 例子: 
        ///  FillDataset(connString, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, 24);
        /// 
        /// 合法的连接
        /// 存储过程名字
        /// 
        /// 表名

        ///     
        /// 分配给存储过程作为输入参数的对象数组
        public static void FillDataset(string connectionString, string spName,
            DataTable dataSet, string[] tableNames,
            params object[] parameterValues)
        {
            if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
            if (dataSet == null) throw new ArgumentNullException("dataSet");
            // Create & open a SqlConnection, and dispose of it after we are done
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();

                // Call the overload that takes a connection in place of the connection string
                FillDataset(connection, spName, dataSet, tableNames, parameterValues);
            }
        }

        /// 
        /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the provided SqlConnection. 
        /// 
        /// 
        /// 例子: 
        ///  FillDataset(conn, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"});
        /// 
        /// 合法的连接
        /// 命令类型 (stored procedure, text, 等)
        /// 存储过程名字或sql命令
        /// 
        /// 表名

        ///     
        public static void FillDataset(SqlConnection connection, CommandType commandType,
            string commandText, DataTable dataSet, string[] tableNames)
        {
            FillDataset(connection, commandType, commandText, dataSet, tableNames, null);
        }

        /// 
        /// Execute a SqlCommand (that returns a resultset) against the specified SqlConnection 
        /// using the provided parameters.
        /// 
        /// 
        /// 例子: 
        ///  FillDataset(conn, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new SqlParameter("@prodid", 24));
        /// 
        /// 合法的连接
        /// 命令类型 (stored procedure, text, 等)
        /// 存储过程名字或sql命令
        /// 
        /// 表名

        /// 
        /// SqlParamter数组
        public static void FillDataset(SqlConnection connection, CommandType commandType,
            string commandText, DataTable dataSet, string[] tableNames,
            params SqlParameter[] commandParameters)
        {
            FillDataset(connection, null, commandType, commandText, dataSet, tableNames, commandParameters);
        }

        /// 
        ///调用存储过程,返回数据集
        /// using the provided parameter values.  This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// 
        /// 
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// 例子: 
        ///  FillDataset(conn, "GetOrders", ds, new string[] {"orders"}, 24, 36);
        /// 
        /// 合法的连接
        /// 存储过程名字
        /// 
        /// 表名

        /// 
        /// 分配给存储过程作为输入参数的对象数组
        public static void FillDataset(SqlConnection connection, string spName, DataTable dataSet, string[] tableNames, params object[] parameterValues)
        {
            if (connection == null) throw new ArgumentNullException("connection");
            if (dataSet == null) throw new ArgumentNullException("dataSet");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes SqlParamters数组
                FillDataset(connection, CommandType.StoredProcedure, spName, dataSet, tableNames, commandParameters);
            }
            else
            {
                // Otherwise we can just call the SP without params
                FillDataset(connection, CommandType.StoredProcedure, spName, dataSet, tableNames);
            }
        }

        /// 
        /// 执行SqlCommand对象,返回数据集
        /// 
        /// 
        /// 例子: 
        ///  FillDataset(trans, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"});
        /// 
        /// 合法的事务
        /// 命令类型 (stored procedure, text, 等)
        /// 存储过程名字或sql命令
        /// 
        /// 表名 
        /// 
        public static void FillDataset(SqlTransaction transaction, CommandType commandType,
            string commandText,
            DataTable dataSet, string[] tableNames)
        {
            FillDataset(transaction, commandType, commandText, dataSet, tableNames, null);
        }

        /// 
        ///执行SqlCommand对象,返回数据集
        /// 
        /// 
        /// 例子: 
        ///  FillDataset(trans, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new SqlParameter("@prodid", 24));
        /// 
        /// 合法的事务
        /// 命令类型 (stored procedure, text, 等)
        /// 存储过程名字或sql命令
        /// 
        /// 表名

        /// 
        /// SqlParamter数组
        public static void FillDataset(SqlTransaction transaction, CommandType commandType,
            string commandText, DataTable dataSet, string[] tableNames,
            params SqlParameter[] commandParameters)
        {
            FillDataset(transaction.Connection, transaction, commandType, commandText, dataSet, tableNames, commandParameters);
        }

        /// 
        /// 执行SqlCommand对象,返回数据集
        /// 
        /// 
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// 例子: 
        ///  FillDataset(trans, "GetOrders", ds, new string[]{"orders"}, 24, 36);
        /// 
        /// 合法的事务
        /// 存储过程名字
        /// 
        /// 表名
        /// 
        /// 分配给存储过程作为输入参数的对象数组
        public static void FillDataset(SqlTransaction transaction, string spName,
            DataTable dataSet, string[] tableNames,
            params object[] parameterValues)
        {
            if (transaction == null) throw new ArgumentNullException("transaction");
            if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
            if (dataSet == null) throw new ArgumentNullException("dataSet");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes SqlParamters数组
                FillDataset(transaction, CommandType.StoredProcedure, spName, dataSet, tableNames, commandParameters);
            }
            else
            {
                // Otherwise we can just call the SP without params
                FillDataset(transaction, CommandType.StoredProcedure, spName, dataSet, tableNames);
            }
        }

        /// 
        ///执行SqlCommand对象,返回数据集
        /// 
        /// 例子: 
        ///  FillDataset(conn, trans, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new SqlParameter("@prodid", 24));
        /// 
        /// 合法的连接
        /// 合法的事务
        /// 命令类型 (stored procedure, text, 等)
        /// 存储过程名字或sql命令
        /// 
        /// 表名
        /// 
        /// SqlParamter数组
        private static void FillDataset(SqlConnection connection, SqlTransaction transaction, CommandType commandType,
            string commandText, DataTable dataSet, string[] tableNames,
            params SqlParameter[] commandParameters)
        {
            if (connection == null) throw new ArgumentNullException("connection");
            if (dataSet == null) throw new ArgumentNullException("dataSet");

            // Create a command and prepare it for execution
            SqlCommand command = new SqlCommand();
            bool mustCloseConnection = false;
            PrepareCommand(command, connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

            // Create the DataAdapter & DataTable
            using (SqlDataAdapter dataAdapter = new SqlDataAdapter(command))
            {

                // Add the table mappings specified by the user
                if (tableNames != null && tableNames.Length > 0)
                {
                    string tableName = "Table";
                    for (int index = 0; index < tableNames.Length; index++)
                    {
                        if (tableNames[index] == null || tableNames[index].Length == 0) throw new ArgumentException("The tableNames parameter must contain a list of tables, a value was provided as null or empty string.", "tableNames");
                        dataAdapter.TableMappings.Add(tableName, tableNames[index]);
                        tableName += (index + 1).ToString();
                    }
                }

                // Fill the DataTable using default values for DataTable names, etc
                dataAdapter.Fill(dataSet);

                // Detach the SqlParameters from the command object, so they can be used again
                command.Parameters.Clear();
            }

            if (mustCloseConnection)
                connection.Close();
        }
        #endregion

        //#region UpdateDataset
        ///// 
        /////  执行SqlCommand对象,返回数据集
        ///// 
        ///// 
        ///// 例子: 
        /////  UpdateDataset(conn, insertCommand, deleteCommand, updateCommand, dataSet, "Order");
        ///// 
        ///// 插入命令对象
        ///// 删除命令对象
        ///// 更新命令对象
        ///// 数据集
        ///// 表名
        //public static void UpdateDataset(SqlCommand insertCommand, SqlCommand deleteCommand, SqlCommand updateCommand, DataTable dataSet, string tableName)
        //{
        //    if (insertCommand == null) throw new ArgumentNullException("insertCommand");
        //    if (deleteCommand == null) throw new ArgumentNullException("deleteCommand");
        //    if (updateCommand == null) throw new ArgumentNullException("updateCommand");
        //    if (tableName == null || tableName.Length == 0) throw new ArgumentNullException("tableName");

        //    // Create a SqlDataAdapter, and dispose of it after we are done
        //    using (SqlDataAdapter dataAdapter = new SqlDataAdapter())
        //    {
        //        // Set the data adapter commands
        //        dataAdapter.UpdateCommand = updateCommand;
        //        dataAdapter.InsertCommand = insertCommand;
        //        dataAdapter.DeleteCommand = deleteCommand;

        //        // Update the dataset changes in the data source
        //        dataAdapter.Update(dataSet, tableName);

        //        // Commit all the changes made to the DataTable
        //        dataSet.AcceptChanges();
        //    }
        //}
        //#endregion

        #region CreateCommand
        /// 
        /// 创建命令对象
        /// a stored procedure and optional parameters to be provided
        /// 
        /// 
        /// 例子: 
        ///  SqlCommand command = CreateCommand(conn, "AddCustomer", "CustomerID", "CustomerName");
        /// 
        /// 合法的连接
        /// 存储过程的名字
        /// 提供给存储过程的作为列名的字符串数组
        /// A valid SqlCommand object
        public static SqlCommand CreateCommand(SqlConnection connection, string spName, params string[] sourceColumns)
        {
            if (connection == null) throw new ArgumentNullException("connection");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // Create a SqlCommand
            SqlCommand cmd = new SqlCommand(spName, connection);
            cmd.CommandType = CommandType.StoredProcedure;

            // If we receive parameter values, we need to figure out where they go
            if ((sourceColumns != null) && (sourceColumns.Length > 0))
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                // Assign the provided source columns to these parameters based on parameter order
                for (int index = 0; index < sourceColumns.Length; index++)
                    commandParameters[index].SourceColumn = sourceColumns[index];

                // Attach the discovered parameters to the SqlCommand object
                AttachParameters(cmd, commandParameters);
            }

            return cmd;
        }
        #endregion

        #region ExecuteNonQueryTypedParams
        /// 
        /// 调用存储过程
        /// 
        /// 合法的连接
        /// 存储过程的名字
        /// 数据行,保存着存储过程的参数值.
        /// 整型
        public static int ExecuteNonQueryTypedParams(String connectionString, String spName, DataRow dataRow)
        {
            if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If the row has values, the store procedure parameters must be initialized
            if (dataRow != null && dataRow.ItemArray.Length > 0)
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                // Set the parameters values
                AssignParameterValues(commandParameters, dataRow);

                return SqlHelper.ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return SqlHelper.ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName);
            }
        }

        /// 
        /// 调用存储过程Execute a stored procedure via a SqlCommand (that returns no resultset) against the specified SqlConnection 
        /// 
        /// 合法的连接
        /// 存储过程的名字
        /// 数据行,保存着存储过程的参数值.
        /// 整型
        public static int ExecuteNonQueryTypedParams(SqlConnection connection, String spName, DataRow dataRow)
        {
            if (connection == null) throw new ArgumentNullException("connection");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If the row has values, the store procedure parameters must be initialized
            if (dataRow != null && dataRow.ItemArray.Length > 0)
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                // Set the parameters values
                AssignParameterValues(commandParameters, dataRow);

                return SqlHelper.ExecuteNonQuery(connection, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return SqlHelper.ExecuteNonQuery(connection, CommandType.StoredProcedure, spName);
            }
        }

        /// 
        /// 调用存储过程
        /// 
        /// 合法的连接
        /// 存储过程的名字
        /// 数据行,保存着存储过程的参数值.
        /// 整型
        public static int ExecuteNonQueryTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)
        {
            if (transaction == null) throw new ArgumentNullException("transaction");
            if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // Sf the row has values, the store procedure parameters must be initialized
            if (dataRow != null && dataRow.ItemArray.Length > 0)
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                // Set the parameters values
                AssignParameterValues(commandParameters, dataRow);

                return SqlHelper.ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return SqlHelper.ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName);
            }
        }
        #endregion

        #region ExecuteDatasetTypedParams
        /// 
        ///调用存储过程
        /// 
        /// 合法的连接
        /// 存储过程的名字
        /// 数据行,保存着存储过程的参数值.
        /// 数据集
        public static DataSet ExecuteDatasetTypedParams(string connectionString, String spName, DataRow dataRow)
        {
            if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            //If the row has values, the store procedure parameters must be initialized
            if (dataRow != null && dataRow.ItemArray.Length > 0)
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                // Set the parameters values
                AssignParameterValues(commandParameters, dataRow);

                return SqlHelper.ExecuteDataset(connectionString, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return SqlHelper.ExecuteDataset(connectionString, CommandType.StoredProcedure, spName);
            }
        }

        /// 
        /// 调用存储过程
        /// 
        /// 合法的连接
        /// 存储过程的名字
        /// 数据行,保存着存储过程的参数值.
        /// 数据集
        public static DataSet ExecuteDatasetTypedParams(SqlConnection connection, String spName, DataRow dataRow)
        {
            if (connection == null) throw new ArgumentNullException("connection");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If the row has values, the store procedure parameters must be initialized
            if (dataRow != null && dataRow.ItemArray.Length > 0)
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                // Set the parameters values
                AssignParameterValues(commandParameters, dataRow);

                return SqlHelper.ExecuteDataset(connection, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return SqlHelper.ExecuteDataset(connection, CommandType.StoredProcedure, spName);
            }
        }

        /// 
        /// 调用存储过程
        /// 
        /// 合法的连接
        /// 存储过程的名字
        /// 数据行,保存着存储过程的参数值.
        /// 数据集
        public static DataSet ExecuteDatasetTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)
        {
            if (transaction == null) throw new ArgumentNullException("transaction");
            if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If the row has values, the store procedure parameters must be initialized
            if (dataRow != null && dataRow.ItemArray.Length > 0)
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                // Set the parameters values
                AssignParameterValues(commandParameters, dataRow);

                return SqlHelper.ExecuteDataset(transaction, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return SqlHelper.ExecuteDataset(transaction, CommandType.StoredProcedure, spName);
            }
        }

        #endregion

        #region ExecuteReaderTypedParams
        /// 
        /// 调用存储过程
        /// 
        /// 合法的连接
        /// 存储过程的名字
        /// 数据行,保存着存储过程的参数值.
        /// SqlDataReader
        public static SqlDataReader ExecuteReaderTypedParams(String connectionString, String spName, DataRow dataRow)
        {
            if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If the row has values, the store procedure parameters must be initialized
            if (dataRow != null && dataRow.ItemArray.Length > 0)
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                // Set the parameters values
                AssignParameterValues(commandParameters, dataRow);

                return SqlHelper.ExecuteReader(connectionString, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return SqlHelper.ExecuteReader(connectionString, CommandType.StoredProcedure, spName);
            }
        }


        /// 
        /// 调用存储过程
        /// 
        /// 合法的连接
        /// 存储过程的名字
        /// 数据行,保存着存储过程的参数值.
        /// SqlDataReader
        public static SqlDataReader ExecuteReaderTypedParams(SqlConnection connection, String spName, DataRow dataRow)
        {
            if (connection == null) throw new ArgumentNullException("connection");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If the row has values, the store procedure parameters must be initialized
            if (dataRow != null && dataRow.ItemArray.Length > 0)
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                // Set the parameters values
                AssignParameterValues(commandParameters, dataRow);

                return SqlHelper.ExecuteReader(connection, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return SqlHelper.ExecuteReader(connection, CommandType.StoredProcedure, spName);
            }
        }

        /// 
        /// 调用存储过程
        /// 
        /// 合法的连接
        /// 存储过程的名字
        /// 数据行,保存着存储过程的参数值.
        /// SqlDataReader
        public static SqlDataReader ExecuteReaderTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)
        {
            if (transaction == null) throw new ArgumentNullException("transaction");
            if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If the row has values, the store procedure parameters must be initialized
            if (dataRow != null && dataRow.ItemArray.Length > 0)
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                // Set the parameters values
                AssignParameterValues(commandParameters, dataRow);

                return SqlHelper.ExecuteReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return SqlHelper.ExecuteReader(transaction, CommandType.StoredProcedure, spName);
            }
        }
        #endregion

        #region ExecuteScalarTypedParams
        /// 
        /// Execute a stored procedure via a SqlCommand (that returns a 1x1 resultset) against the database specified in 
        /// the connection string using the dataRow column values as the stored procedure's parameters values.
        /// This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// 
        /// 合法的连接
        /// 存储过程的名字
        /// 数据行,保存着存储过程的参数值.
        /// 对象
        public static object ExecuteScalarTypedParams(String connectionString, String spName, DataRow dataRow)
        {
            if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If the row has values, the store procedure parameters must be initialized
            if (dataRow != null && dataRow.ItemArray.Length > 0)
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                // Set the parameters values
                AssignParameterValues(commandParameters, dataRow);

                return SqlHelper.ExecuteScalar(connectionString, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return SqlHelper.ExecuteScalar(connectionString, CommandType.StoredProcedure, spName);
            }
        }

        /// 
        /// 返回数量
        /// 
        /// 合法的连接
        /// 存储过程的名字
        /// 数据行,保存着存储过程的参数值.
        /// 对象
        public static object ExecuteScalarTypedParams(SqlConnection connection, String spName, DataRow dataRow)
        {
            if (connection == null) throw new ArgumentNullException("connection");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If the row has values, the store procedure parameters must be initialized
            if (dataRow != null && dataRow.ItemArray.Length > 0)
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                // Set the parameters values
                AssignParameterValues(commandParameters, dataRow);

                return SqlHelper.ExecuteScalar(connection, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return SqlHelper.ExecuteScalar(connection, CommandType.StoredProcedure, spName);
            }
        }

        /// 
        ///返回数量
        /// 
        /// 合法的连接
        /// 存储过程的名字
        /// 数据行,保存着存储过程的参数值.
        /// 对象
        public static object ExecuteScalarTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)
        {
            if (transaction == null) throw new ArgumentNullException("transaction");
            if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If the row has values, the store procedure parameters must be initialized
            if (dataRow != null && dataRow.ItemArray.Length > 0)
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                // Set the parameters values
                AssignParameterValues(commandParameters, dataRow);

                return SqlHelper.ExecuteScalar(transaction, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return SqlHelper.ExecuteScalar(transaction, CommandType.StoredProcedure, spName);
            }
        }
        #endregion

        #region ExecuteXmlReaderTypedParams
        /// 
        /// 读取xml,返回XmlReader
        /// 
        /// 合法的连接
        /// 存储过程的名字
        /// 数据行,保存着存储过程的参数值.
        /// XmlReader
        public static XmlReader ExecuteXmlReaderTypedParams(SqlConnection connection, String spName, DataRow dataRow)
        {
            if (connection == null) throw new ArgumentNullException("connection");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If the row has values, the store procedure parameters must be initialized
            if (dataRow != null && dataRow.ItemArray.Length > 0)
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                // Set the parameters values
                AssignParameterValues(commandParameters, dataRow);

                return SqlHelper.ExecuteXmlReader(connection, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return SqlHelper.ExecuteXmlReader(connection, CommandType.StoredProcedure, spName);
            }
        }

        /// 
        ///读取xml,返回XmlReader
        /// 
        /// 合法的连接
        /// 存储过程的名字
        /// 数据行,保存着存储过程的参数值.
        /// XmlReader
        public static XmlReader ExecuteXmlReaderTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)
        {
            if (transaction == null) throw new ArgumentNullException("transaction");
            if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            // If the row has values, the store procedure parameters must be initialized
            if (dataRow != null && dataRow.ItemArray.Length > 0)
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                // Set the parameters values
                AssignParameterValues(commandParameters, dataRow);

                return SqlHelper.ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return SqlHelper.ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName);
            }
        }
        #endregion

    }

    /// 
    /// SqlCommand缓存类
    /// 
    public sealed class SqlHelperParameterCache
    {
        #region private methods, variables, and constructors

        //Since this class provides only static methods, make the default constructor private to prevent 
        //instances from being created with "new SqlHelperParameterCache()"
        private SqlHelperParameterCache() { }

        private static Hashtable paramCache = Hashtable.Synchronized(new Hashtable());

        /// 
        /// 取出存储过程的参数列表
        /// 
        /// 合法的连接
        /// 存储过程的名字
        /// 是否包含返回值参数
        /// SqlParameter数组
        private static SqlParameter[] DiscoverSpParameterSet(SqlConnection connection, string spName, bool includeReturnValueParameter)
        {
            if (connection == null) throw new ArgumentNullException("connection");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            SqlCommand cmd = new SqlCommand(spName, connection);
            cmd.CommandType = CommandType.StoredProcedure;

            connection.Open();
            SqlCommandBuilder.DeriveParameters(cmd);
            connection.Close();

            if (!includeReturnValueParameter)
            {
                cmd.Parameters.RemoveAt(0);
            }

            SqlParameter[] discoveredParameters = new SqlParameter[cmd.Parameters.Count];

            cmd.Parameters.CopyTo(discoveredParameters, 0);

            // Init the parameters with a DBNull value
            foreach (SqlParameter discoveredParameter in discoveredParameters)
            {
                discoveredParameter.Value = DBNull.Value;
            }
            return discoveredParameters;
        }

        /// 
        /// 深度复制SqlParamter数组
        /// 
        /// 原始SqlParameter数组
        /// SqlParameter数组
        private static SqlParameter[] CloneParameters(SqlParameter[] originalParameters)
        {
            SqlParameter[] clonedParameters = new SqlParameter[originalParameters.Length];

            for (int i = 0, j = originalParameters.Length; i < j; i++)
            {
                clonedParameters[i] = (SqlParameter)((ICloneable)originalParameters[i]).Clone();
            }

            return clonedParameters;
        }

        #endregion private methods, variables, and constructors

        #region caching functions

        /// 
        /// 缓存参数数组
        /// 
        /// 合法的连接
        /// 存储过程的名字或sql命令
        /// SqlParamters数组 to be cached
        public static void CacheParameterSet(string connectionString, string commandText, params SqlParameter[] commandParameters)
        {
            if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
            if (commandText == null || commandText.Length == 0) throw new ArgumentNullException("commandText");

            string hashKey = connectionString + ":" + commandText;

            paramCache[hashKey] = commandParameters;
        }

        /// 
        /// 从缓存获取SqlCommand数组
        /// 
        /// 合法的连接
        /// 存储过程的名字或sql命令
        /// SqlParamters数组
        public static SqlParameter[] GetCachedParameterSet(string connectionString, string commandText)
        {
            if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
            if (commandText == null || commandText.Length == 0) throw new ArgumentNullException("commandText");

            string hashKey = connectionString + ":" + commandText;

            SqlParameter[] cachedParameters = paramCache[hashKey] as SqlParameter[];
            if (cachedParameters == null)
            {
                return null;
            }
            else
            {
                return CloneParameters(cachedParameters);
            }
        }

        #endregion caching functions

        #region Parameter Discovery Functions

        /// 
        /// 取出存储过程的参数集
        /// 
        /// 
        /// 查询数据库,并取出存储过程的参数集缓存起来
        /// 
        /// 合法的连接
        /// 存储过程的名字
        /// SqlParamters数组
        public static SqlParameter[] GetSpParameterSet(string connectionString, string spName)
        {
            return GetSpParameterSet(connectionString, spName, false);
        }

        /// 
        /// 取出存储过程的参数集
        /// 
        /// 
        /// 查询数据库,并取出存储过程的参数集缓存起来
        /// 
        /// 合法的连接
        /// 存储过程的名字
        /// A bool value indicating whether the return value parameter should be included in the results
        /// SqlParamters数组
        public static SqlParameter[] GetSpParameterSet(string connectionString, string spName, bool includeReturnValueParameter)
        {
            if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                return GetSpParameterSetInternal(connection, spName, includeReturnValueParameter);
            }
        }

        /// 
        /// 取出存储过程的参数集
        /// 
        /// 
        /// 查询数据库,并取出存储过程的参数集缓存起来
        /// 
        /// 合法的连接
        /// 存储过程的名字
        /// SqlParamters数组
        internal static SqlParameter[] GetSpParameterSet(SqlConnection connection, string spName)
        {
            return GetSpParameterSet(connection, spName, false);
        }

        /// 
        /// 取出存储过程的参数集
        /// 
        /// 
        /// 查询数据库,并取出存储过程的参数集缓存起来
        /// 
        /// 合法的连接
        /// 存储过程的名字
        /// 是否包含返回值参数
        /// SqlParamters数组
        internal static SqlParameter[] GetSpParameterSet(SqlConnection connection, string spName, bool includeReturnValueParameter)
        {
            if (connection == null) throw new ArgumentNullException("connection");
            using (SqlConnection clonedConnection = (SqlConnection)((ICloneable)connection).Clone())
            {
                return GetSpParameterSetInternal(clonedConnection, spName, includeReturnValueParameter);
            }
        }

        /// 
        /// 取出存储过程的参数集
        /// 
        /// 合法的连接
        /// 存储过程的名字
        /// A bool value indicating whether the return value parameter should be included in the results
        /// SqlParamters数组
        private static SqlParameter[] GetSpParameterSetInternal(SqlConnection connection, string spName, bool includeReturnValueParameter)
        {
            if (connection == null) throw new ArgumentNullException("connection");
            if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

            string hashKey = connection.ConnectionString + ":" + spName + (includeReturnValueParameter ? ":include ReturnValue Parameter" : "");

            SqlParameter[] cachedParameters;

            cachedParameters = paramCache[hashKey] as SqlParameter[];
            if (cachedParameters == null)
            {
                SqlParameter[] spParameters = DiscoverSpParameterSet(connection, spName, includeReturnValueParameter);
                paramCache[hashKey] = spParameters;
                cachedParameters = spParameters;
            }

            return CloneParameters(cachedParameters);
        }

        #endregion Parameter Discovery Functions

    }
}






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