SqlHelper(带详细中文注释)

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

namespace hkszyy
{
/// <summary>
/// SqlServer数据访问帮助类
/// </summary>
public sealed class SqlHelper
{
#region 私有构造函数和方法

private SqlHelper() {}

/// <summary>
/// 将SqlParameter参数数组(参数值)分配给SqlCommand命令.
/// 这个方法将给任何一个参数分配DBNull.Value;
/// 该操作将阻止默认值的使用.
/// </summary>
/// <param name="command">命令名</param>
/// <param name="commandParameters">SqlParameters数组</param>
private static void AttachParameters(SqlCommand command, SqlParameter[] commandParameters)
{
if( command == null ) throw new ArgumentNullException( "command" );
if( commandParameters != null )
{
foreach (SqlParameter p in commandParameters)
{
if( p != null )
{
// 检查未分配值的输出参数,将其分配以DBNull.Value.
if ( ( p.Direction == ParameterDirection.InputOutput || p.Direction == ParameterDirection.Input ) &&
(p.Value == null))
{
p.Value = DBNull.Value;
}
command.Parameters.Add(p);
}
}
}
}

/// <summary>
/// 将DataRow类型的列值分配到SqlParameter参数数组.
/// </summary>
/// <param name="commandParameters">要分配值的SqlParameter参数数组</param>
/// <param name="dataRow">将要分配给存储过程参数的DataRow</param>
private static void AssignParameterValues(SqlParameter[] commandParameters, DataRow dataRow)
{
if ((commandParameters == null) || (dataRow == null))
{
return;
}

int i = 0;
// 设置参数值
foreach(SqlParameter commandParameter in commandParameters)
{
// 创建参数名称,如果不存在,只抛出一个异常.
if( commandParameter.ParameterName == null ||
commandParameter.ParameterName.Length <= 1 )
throw new Exception(
string.Format("请提供参数{0}一个有效的名称{1}.", i, commandParameter.ParameterName ) );
// 从dataRow的表中获取为参数数组中数组名称的列的索引.
// 如果存在和参数名称相同的列,则将列值赋给当前名称的参数.
if (dataRow.Table.Columns.IndexOf(commandParameter.ParameterName.Substring(1)) != -1)
commandParameter.Value = dataRow[commandParameter.ParameterName.Substring(1)];
i++;
}
}

/// <summary>
/// 将一个对象数组分配给SqlParameter参数数组.
/// </summary>
/// <param name="commandParameters">要分配值的SqlParameter参数数组</param>
/// <param name="parameterValues">将要分配给存储过程参数的对象数组</param>
private static void AssignParameterValues(SqlParameter[] commandParameters, object[] parameterValues)
{
if ((commandParameters == null) || (parameterValues == null))
{
return;
}

// 确保对象数组个数与参数个数匹配,如果不匹配,抛出一个异常.
if (commandParameters.Length != parameterValues.Length)
{
throw new ArgumentException("参数值个数与参数不匹配.");
}

// 给参数赋值
for (int i = 0, j = commandParameters.Length; i < j; i++)
{
// If the current array value derives from IDbDataParameter, then assign its Value property
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];
}
}
}

/// <summary>
/// 预处理用户提供的命令,数据库连接/事务/命令类型/参数
/// </summary>
/// <param name="command">要处理的SqlCommand</param>
/// <param name="connection">数据库连接</param>
/// <param name="transaction">一个有效的事务或者是null值</param>
/// <param name="commandType">命令类型 (存储过程,命令文本, 其它.)</param>
/// <param name="commandText">存储过程名或都T-SQL命令文本</param>
/// <param name="commandParameters">和命令相关联的SqlParameter参数数组,如果没有参数为'null'</param>
/// <param name="mustCloseConnection"><c>true</c> 如果连接是打开的,则为true,其它情况下为false.</param>
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 the provided connection is not open, we will open it
if (connection.State != ConnectionState.Open)
{
mustCloseConnection = true;
connection.Open();
}
else
{
mustCloseConnection = false;
}

// 给命令分配一个数据库连接.
command.Connection = connection;

// 设置命令文本(存储过程名或SQL语句)
command.CommandText = commandText;

// 分配事务
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;
}

// 设置命令类型.
command.CommandType = commandType;

// 分配命令参数
if (commandParameters != null)
{
AttachParameters(command, commandParameters);
}
return;
}

#endregion 私有构造函数和方法结束

#region ExecuteNonQuery命令

/// <summary>
/// 执行指定连接字符串,类型的SqlCommand.
/// </summary>
/// <remarks>
/// 示例:
/// int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders");
/// </remarks>
/// <param name="connectionString">一个有效的数据库连接字符串</param>
/// <param name="commandType">命令类型 (存储过程,命令文本, 其它.)</param>
/// <param name="commandText">存储过程名称或SQL语句</param>
/// <returns>返回命令影响的行数</returns>
public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText)
{
return ExecuteNonQuery(connectionString, commandType, commandText, (SqlParameter[])null);
}

/// <summary>
/// 执行指定连接字符串,类型的SqlCommand.如果没有提供参数,不返回结果.
/// </summary>
/// <remarks>
/// 示例:
/// int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
/// </remarks>
/// <param name="connectionString">一个有效的数据库连接字符串</param>
/// <param name="commandType">命令类型 (存储过程,命令文本, 其它.)</param>
/// <param name="commandText">存储过程名称或SQL语句</param>
/// <param name="commandParameters">SqlParameter参数数组</param>
/// <returns>返回命令影响的行数</returns>
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);
}
}

/// <summary>
/// 执行指定连接字符串的存储过程,将对象数组的值赋给存储过程参数,
/// 此方法需要在参数缓存方法中探索参数并生成参数.
/// </summary>
/// <remarks>
/// 这个方法没有提供访问输出参数和返回值.
/// 示例:
/// int result = ExecuteNonQuery(connString, "PublishOrders", 24, 36);
/// </remarks>
/// <param name="connectionString">一个有效的数据库连接字符串/param>
/// <param name="spName">存储过程名称</param>
/// <param name="parameterValues">分配到存储过程输入参数的对象数组</param>
/// <returns>返回受影响的行数</returns>
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" );

// 如果存在参数值
if ((parameterValues != null) && (parameterValues.Length > 0))
{
// 从探索存储过程参数(加载到缓存)并分配给存储过程参数数组.
SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

// 给存储过程参数赋值
AssignParameterValues(commandParameters, parameterValues);

return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName, commandParameters);
}
else
{
// 没有参数情况下
return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName);
}
}

/// <summary>
/// 执行指定数据库连接对象的命令
/// </summary>
/// <remarks>
/// 示例:
/// int result = ExecuteNonQuery(conn, CommandType.StoredProcedure, "PublishOrders");
/// </remarks>
/// <param name="connection">一个有效的数据库连接对象</param>
/// <param name="commandType">命令类型(存储过程,命令文本或其它.)</param>
/// <param name="commandText">存储过程名称或T-SQL语句</param>
/// <returns>返回影响的行数</returns>
public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType, string commandText)
{
return ExecuteNonQuery(connection, commandType, commandText, (SqlParameter[])null);
}

/// <summary>
/// 执行指定数据库连接对象的命令
/// </summary>
/// <remarks>
/// 示例:
/// int result = ExecuteNonQuery(conn, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
/// </remarks>
/// <param name="connection">一个有效的数据库连接对象</param>
/// <param name="commandType">命令类型(存储过程,命令文本或其它.)</param>
/// <param name="commandText">T存储过程名称或T-SQL语句</param>
/// <param name="commandParameters">SqlParamter参数数组</param>
/// <returns>返回影响的行数</returns>
public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
{
if( connection == null ) throw new ArgumentNullException( "connection" );

// 创建SqlCommand命令,并进行预处理
SqlCommand cmd = new SqlCommand();
bool mustCloseConnection = false;
PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection );

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

// 清除参数,以便再次使用.
cmd.Parameters.Clear();
if( mustCloseConnection )
connection.Close();
return retval;
}

/// <summary>
/// 执行指定数据库连接对象的命令,将对象数组的值赋给存储过程参数.
/// </summary>
/// <remarks>
/// 此方法不提供访问存储过程输出参数和返回值
/// 示例:
/// int result = ExecuteNonQuery(conn, "PublishOrders", 24, 36);
/// </remarks>
/// <param name="connection">一个有效的数据库连接对象</param>
/// <param name="spName">存储过程名</param>
/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param>
/// <returns>返回影响的行数</returns>
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" );

// 如果有参数值
if ((parameterValues != null) && (parameterValues.Length > 0))
{
// 从缓存中加载存储过程参数
SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

// 给存储过程分配参数值
AssignParameterValues(commandParameters, parameterValues);

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

/// <summary>
/// 执行带事务的SqlCommand.
/// </summary>
/// <remarks>
/// 示例.:
/// int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "PublishOrders");
/// </remarks>
/// <param name="transaction">一个有效的数据库连接对象</param>
/// <param name="commandType">命令类型(存储过程,命令文本或其它.)</param>
/// <param name="commandText">存储过程名称或T-SQL语句</param>
/// <returns>返回影响的行数/returns>
public static int ExecuteNonQuery(SqlTransaction transaction, CommandType commandType, string commandText)
{
return ExecuteNonQuery(transaction, commandType, commandText, (SqlParameter[])null);
}

/// <summary>
/// 执行带事务的SqlCommand(指定参数).
/// </summary>
/// <remarks>
/// 示例:
/// int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
/// </remarks>
/// <param name="transaction">一个有效的数据库连接对象</param>
/// <param name="commandType">命令类型(存储过程,命令文本或其它.)</param>
/// <param name="commandText">存储过程名称或T-SQL语句</param>
/// <param name="commandParameters">SqlParamter参数数组</param>
/// <returns>返回影响的行数</returns>
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" );

// 预处理
SqlCommand cmd = new SqlCommand();
bool mustCloseConnection = false;
PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection );

// 执行
int retval = cmd.ExecuteNonQuery();

// 清除参数集,以便再次使用.
cmd.Parameters.Clear();
return retval;
}

/// <summary>
/// 执行带事务的SqlCommand(指定参数值).
/// </summary>
/// <remarks>
/// 此方法不提供访问存储过程输出参数和返回值
/// 示例:
/// int result = ExecuteNonQuery(conn, trans, "PublishOrders", 24, 36);
/// </remarks>
/// <param name="transaction">一个有效的数据库连接对象</param>
/// <param name="spName">存储过程名</param>
/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param>
/// <returns>返回受影响的行数</returns>
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" );

// 如果有参数值
if ((parameterValues != null) && (parameterValues.Length > 0))
{
// 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()
SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

// 给存储过程参数赋值
AssignParameterValues(commandParameters, parameterValues);

// 调用重载方法
return ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName, commandParameters);
}
else
{
// 没有参数值
return ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName);
}
}

#endregion ExecuteNonQuery方法结束

#region ExecuteDataset方法

/// <summary>
/// 执行指定数据库连接字符串的命令,返回DataSet.
/// </summary>
/// <remarks>
/// 示例:
/// DataSet ds = ExecuteDataset(connString, CommandType.StoredProcedure, "GetOrders");
/// </remarks>
/// <param name="connectionString">一个有效的数据库连接字符串</param>
/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>
/// <param name="commandText">存储过程名称或T-SQL语句</param>
/// <returns>返回一个包含结果集的DataSet</returns>
public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText)
{
return ExecuteDataset(connectionString, commandType, commandText, (SqlParameter[])null);
}

/// <summary>
/// 执行指定数据库连接字符串的命令,返回DataSet.
/// </summary>
/// <remarks>
/// 示例:
/// DataSet ds = ExecuteDataset(connString, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
/// </remarks>
/// <param name="connectionString">一个有效的数据库连接字符串</param>
/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>
/// <param name="commandText">存储过程名称或T-SQL语句</param>
/// <param name="commandParameters">SqlParamters参数数组</param>
/// <returns>返回一个包含结果集的DataSet</returns>
public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
{
if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );

// 创建并打开数据库连接对象,操作完成释放对象.
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();

// 调用指定数据库连接字符串重载方法.
return ExecuteDataset(connection, commandType, commandText, commandParameters);
}
}

/// <summary>
/// 执行指定数据库连接字符串的命令,直接提供参数值,返回DataSet.
/// </summary>
/// <remarks>
/// 此方法不提供访问存储过程输出参数和返回值.
/// 示例:
/// DataSet ds = ExecuteDataset(connString, "GetOrders", 24, 36);
/// </remarks>
/// <param name="connectionString">一个有效的数据库连接字符串</param>
/// <param name="spName">存储过程名</param>
/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param>
/// <returns>返回一个包含结果集的DataSet</returns>
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 ((parameterValues != null) && (parameterValues.Length > 0))
{
// 从缓存中检索存储过程参数
SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

// 给存储过程参数分配值
AssignParameterValues(commandParameters, parameterValues);

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

/// <summary>
/// 执行指定数据库连接对象的命令,返回DataSet.
/// </summary>
/// <remarks>
/// 示例:
/// DataSet ds = ExecuteDataset(conn, CommandType.StoredProcedure, "GetOrders");
/// </remarks>
/// <param name="connection">一个有效的数据库连接对象</param>
/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>
/// <param name="commandText">存储过程名或T-SQL语句</param>
/// <returns>返回一个包含结果集的DataSet</returns>
public static DataSet ExecuteDataset(SqlConnection connection, CommandType commandType, string commandText)
{
return ExecuteDataset(connection, commandType, commandText, (SqlParameter[])null);
}

/// <summary>
/// 执行指定数据库连接对象的命令,指定存储过程参数,返回DataSet.
/// </summary>
/// <remarks>
/// 示例:
/// DataSet ds = ExecuteDataset(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
/// </remarks>
/// <param name="connection">一个有效的数据库连接对象</param>
/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>
/// <param name="commandText">存储过程名或T-SQL语句</param>
/// <param name="commandParameters">SqlParamter参数数组</param>
/// <returns>返回一个包含结果集的DataSet</returns>
public static DataSet ExecuteDataset(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
{
if( connection == null ) throw new ArgumentNullException( "connection" );

// 预处理
SqlCommand cmd = new SqlCommand();
bool mustCloseConnection = false;
PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection );

// 创建SqlDataAdapter和DataSet.
using( SqlDataAdapter da = new SqlDataAdapter(cmd) )
{
DataSet ds = new DataSet();

// 填充DataSet.
da.Fill(ds);

cmd.Parameters.Clear();

if( mustCloseConnection )
connection.Close();

return ds;
}
}

/// <summary>
/// 执行指定数据库连接对象的命令,指定参数值,返回DataSet.
/// </summary>
/// <remarks>
/// 此方法不提供访问存储过程输入参数和返回值.
/// 示例.:
/// DataSet ds = ExecuteDataset(conn, "GetOrders", 24, 36);
/// </remarks>
/// <param name="connection">一个有效的数据库连接对象</param>
/// <param name="spName">存储过程名</param>
/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param>
/// <returns>返回一个包含结果集的DataSet</returns>
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 ((parameterValues != null) && (parameterValues.Length > 0))
{
// 比缓存中加载存储过程参数
SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

// 给存储过程参数分配值
AssignParameterValues(commandParameters, parameterValues);

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

/// <summary>
/// 执行指定事务的命令,返回DataSet.
/// </summary>
/// <remarks>
/// 示例:
/// DataSet ds = ExecuteDataset(trans, CommandType.StoredProcedure, "GetOrders");
/// </remarks>
/// <param name="transaction">事务</param>
/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>
/// <param name="commandText">存储过程名或T-SQL语句</param>
/// <returns>返回一个包含结果集的DataSet</returns>
public static DataSet ExecuteDataset(SqlTransaction transaction, CommandType commandType, string commandText)
{
return ExecuteDataset(transaction, commandType, commandText, (SqlParameter[])null);
}

/// <summary>
/// 执行指定事务的命令,指定参数,返回DataSet.
/// </summary>
/// <remarks>
/// 示例:
/// DataSet ds = ExecuteDataset(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
/// </remarks>
/// <param name="transaction">事务</param>
/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>
/// <param name="commandText">存储过程名或T-SQL语句</param>
/// <param name="commandParameters">SqlParamter参数数组</param>
/// <returns>返回一个包含结果集的DataSet</returns>
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" );

// 预处理
SqlCommand cmd = new SqlCommand();
bool mustCloseConnection = false;
PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection );

// 创建 DataAdapter & DataSet
using( SqlDataAdapter da = new SqlDataAdapter(cmd) )
{
DataSet ds = new DataSet();
da.Fill(ds);
cmd.Parameters.Clear();
return ds;
}
}

/// <summary>
/// 执行指定事务的命令,指定参数值,返回DataSet.
/// </summary>
/// <remarks>
/// 此方法不提供访问存储过程输入参数和返回值.
/// 示例.:
/// DataSet ds = ExecuteDataset(trans, "GetOrders", 24, 36);
/// </remarks>
/// <param name="transaction">事务</param>
/// <param name="spName">存储过程名</param>
/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param>
/// <returns>返回一个包含结果集的DataSet</returns>
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 ((parameterValues != null) && (parameterValues.Length > 0))
{
// 从缓存中加载存储过程参数
SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

// 给存储过程参数分配值
AssignParameterValues(commandParameters, parameterValues);

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

#endregion ExecuteDataset数据集命令结束

#region ExecuteReader 数据阅读器

/// <summary>
/// 枚举,标识数据库连接是由SqlHelper提供还是由调用者提供
/// </summary>
private enum SqlConnectionOwnership
{
/// <summary>由SqlHelper提供连接</summary>
Internal,
/// <summary>由调用者提供连接</summary>
External
}

/// <summary>
/// 执行指定数据库连接对象的数据阅读器.
/// </summary>
/// <remarks>
/// 如果是SqlHelper打开连接,当连接关闭DataReader也将关闭.
/// 如果是调用都打开连接,DataReader由调用都管理.
/// </remarks>
/// <param name="connection">一个有效的数据库连接对象</param>
/// <param name="transaction">一个有效的事务,或者为 'null'</param>
/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>
/// <param name="commandText">存储过程名或T-SQL语句</param>
/// <param name="commandParameters">SqlParameters参数数组,如果没有参数则为'null'</param>
/// <param name="connectionOwnership">标识数据库连接对象是由调用者提供还是由SqlHelper提供</param>
/// <returns>返回包含结果集的SqlDataReader</returns>
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;
// 创建命令
SqlCommand cmd = new SqlCommand();
try
{
PrepareCommand(cmd, connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection );

// 创建数据阅读器
SqlDataReader dataReader;

if (connectionOwnership == SqlConnectionOwnership.External)
{
dataReader = cmd.ExecuteReader();
}
else
{
dataReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
}

// 清除参数,以便再次使用..
// 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;
}
}

/// <summary>
/// 执行指定数据库连接字符串的数据阅读器.
/// </summary>
/// <remarks>
/// 示例:
/// SqlDataReader dr = ExecuteReader(connString, CommandType.StoredProcedure, "GetOrders");
/// </remarks>
/// <param name="connectionString">一个有效的数据库连接字符串</param>
/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>
/// <param name="commandText">存储过程名或T-SQL语句</param>
/// <returns>返回包含结果集的SqlDataReader</returns>
public static SqlDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText)
{
return ExecuteReader(connectionString, commandType, commandText, (SqlParameter[])null);
}

/// <summary>
/// 执行指定数据库连接字符串的数据阅读器,指定参数.
/// </summary>
/// <remarks>
/// 示例:
/// SqlDataReader dr = ExecuteReader(connString, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
/// </remarks>
/// <param name="connectionString">一个有效的数据库连接字符串</param>
/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>
/// <param name="commandText">存储过程名或T-SQL语句</param>
/// <param name="commandParameters">SqlParamter参数数组(new SqlParameter("@prodid", 24))</param>
/// <returns>返回包含结果集的SqlDataReader</returns>
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();

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;
}

}

/// <summary>
/// 执行指定数据库连接字符串的数据阅读器,指定参数值.
/// </summary>
/// <remarks>
/// 此方法不提供访问存储过程输出参数和返回值参数.
/// 示例:
/// SqlDataReader dr = ExecuteReader(connString, "GetOrders", 24, 36);
/// </remarks>
/// <param name="connectionString">一个有效的数据库连接字符串</param>
/// <param name="spName">存储过程名</param>
/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param>
/// <returns>返回包含结果集的SqlDataReader</returns>
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 ((parameterValues != null) && (parameterValues.Length > 0))
{
SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

AssignParameterValues(commandParameters, parameterValues);

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

/// <summary>
/// 执行指定数据库连接对象的数据阅读器.
/// </summary>
/// <remarks>
/// 示例:
/// SqlDataReader dr = ExecuteReader(conn, CommandType.StoredProcedure, "GetOrders");
/// </remarks>
/// <param name="connection">一个有效的数据库连接对象</param>
/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>
/// <param name="commandText">存储过程名或T-SQL语句</param>
/// <returns>返回包含结果集的SqlDataReader</returns>
public static SqlDataReader ExecuteReader(SqlConnection connection, CommandType commandType, string commandText)
{
return ExecuteReader(connection, commandType, commandText, (SqlParameter[])null);
}

/// <summary>
/// [调用者方式]执行指定数据库连接对象的数据阅读器,指定参数.
/// </summary>
/// <remarks>
/// 示例:
/// SqlDataReader dr = ExecuteReader(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
/// </remarks>
/// <param name="connection">一个有效的数据库连接对象</param>
/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>
/// <param name="commandText">命令类型 (存储过程,命令文本或其它)</param>
/// <param name="commandParameters">SqlParamter参数数组</param>
/// <returns>返回包含结果集的SqlDataReader</returns>
public static SqlDataReader ExecuteReader(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
{
return ExecuteReader(connection, (SqlTransaction)null, commandType, commandText, commandParameters, SqlConnectionOwnership.External);
}

/// <summary>
/// [调用者方式]执行指定数据库连接对象的数据阅读器,指定参数值.
/// </summary>
/// <remarks>
/// 此方法不提供访问存储过程输出参数和返回值参数.
/// 示例:
/// SqlDataReader dr = ExecuteReader(conn, "GetOrders", 24, 36);
/// </remarks>
/// <param name="connection">一个有效的数据库连接对象</param>
/// <param name="spName">T存储过程名</param>
/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param>
/// <returns>返回包含结果集的SqlDataReader</returns>
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 ((parameterValues != null) && (parameterValues.Length > 0))
{
SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

AssignParameterValues(commandParameters, parameterValues);

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

/// <summary>
/// [调用者方式]执行指定数据库事务的数据阅读器,指定参数值.
/// </summary>
/// <remarks>
/// 示例:
/// SqlDataReader dr = ExecuteReader(trans, CommandType.StoredProcedure, "GetOrders");
/// </remarks>
/// <param name="transaction">一个有效的连接事务</param>
/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>
/// <param name="commandText">存储过程名称或T-SQL语句</param>
/// <returns>返回包含结果集的SqlDataReader</returns>
public static SqlDataReader ExecuteReader(SqlTransaction transaction, CommandType commandType, string commandText)
{
return ExecuteReader(transaction, commandType, commandText, (SqlParameter[])null);
}

/// <summary>
/// [调用者方式]执行指定数据库事务的数据阅读器,指定参数.
/// </summary>
/// <remarks>
/// 示例:
/// SqlDataReader dr = ExecuteReader(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
/// </remarks>
/// <param name="transaction">一个有效的连接事务</param>
/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>
/// <param name="commandText">存储过程名称或T-SQL语句</param>
/// <param name="commandParameters">分配给命令的SqlParamter参数数组</param>
/// <returns>返回包含结果集的SqlDataReader</returns>
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" );

return ExecuteReader(transaction.Connection, transaction, commandType, commandText, commandParameters, SqlConnectionOwnership.External);
}

/// <summary>
/// [调用者方式]执行指定数据库事务的数据阅读器,指定参数值.
/// </summary>
/// <remarks>
/// 此方法不提供访问存储过程输出参数和返回值参数.
///
/// 示例:
/// SqlDataReader dr = ExecuteReader(trans, "GetOrders", 24, 36);
/// </remarks>
/// <param name="transaction">一个有效的连接事务</param>
/// <param name="spName">存储过程名称</param>
/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param>
/// <returns>返回包含结果集的SqlDataReader</returns>
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" );

// 如果有参数值
if ((parameterValues != null) && (parameterValues.Length > 0))
{
SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

AssignParameterValues(commandParameters, parameterValues);

return ExecuteReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
}
else
{
// 没有参数值
return ExecuteReader(transaction, CommandType.StoredProcedure, spName);
}
}

#endregion ExecuteReader数据阅读器

#region ExecuteScalar 返回结果集中的第一行第一列

/// <summary>
/// 执行指定数据库连接字符串的命令,返回结果集中的第一行第一列.
/// </summary>
/// <remarks>
/// 示例:
/// int orderCount = (int)ExecuteScalar(connString, CommandType.StoredProcedure, "GetOrderCount");
/// </remarks>
/// <param name="connectionString">一个有效的数据库连接字符串</param>
/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>
/// <param name="commandText">存储过程名称或T-SQL语句</param>
/// <returns>返回结果集中的第一行第一列</returns>
public static object ExecuteScalar(string connectionString, CommandType commandType, string commandText)
{
// 执行参数为空的方法
return ExecuteScalar(connectionString, commandType, commandText, (SqlParameter[])null);
}

/// <summary>
/// 执行指定数据库连接字符串的命令,指定参数,返回结果集中的第一行第一列.
/// </summary>
/// <remarks>
/// 示例:
/// int orderCount = (int)ExecuteScalar(connString, CommandType.StoredProcedure, "GetOrderCount", new SqlParameter("@prodid", 24));
/// </remarks>
/// <param name="connectionString">一个有效的数据库连接字符串</param>
/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>
/// <param name="commandText">存储过程名称或T-SQL语句</param>
/// <param name="commandParameters">分配给命令的SqlParamter参数数组</param>
/// <returns>返回结果集中的第一行第一列</returns>
public static object ExecuteScalar(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
{
if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );
// 创建并打开数据库连接对象,操作完成释放对象.
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();

// 调用指定数据库连接字符串重载方法.
return ExecuteScalar(connection, commandType, commandText, commandParameters);
}
}

/// <summary>
/// 执行指定数据库连接字符串的命令,指定参数值,返回结果集中的第一行第一列.
/// </summary>
/// <remarks>
/// 此方法不提供访问存储过程输出参数和返回值参数.
///
/// 示例:
/// int orderCount = (int)ExecuteScalar(connString, "GetOrderCount", 24, 36);
/// </remarks>
/// <param name="connectionString">一个有效的数据库连接字符串</param>
/// <param name="spName">存储过程名称</param>
/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param>
/// <returns>返回结果集中的第一行第一列</returns>
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" );

// 如果有参数值
if ((parameterValues != null) && (parameterValues.Length > 0))
{
// 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()
SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

// 给存储过程参数赋值
AssignParameterValues(commandParameters, parameterValues);

// 调用重载方法
return ExecuteScalar(connectionString, CommandType.StoredProcedure, spName, commandParameters);
}
else
{
// 没有参数值
return ExecuteScalar(connectionString, CommandType.StoredProcedure, spName);
}
}

/// <summary>
/// 执行指定数据库连接对象的命令,返回结果集中的第一行第一列.
/// </summary>
/// <remarks>
/// 示例:
/// int orderCount = (int)ExecuteScalar(conn, CommandType.StoredProcedure, "GetOrderCount");
/// </remarks>
/// <param name="connection">一个有效的数据库连接对象</param>
/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>
/// <param name="commandText">存储过程名称或T-SQL语句</param>
/// <returns>返回结果集中的第一行第一列</returns>
public static object ExecuteScalar(SqlConnection connection, CommandType commandType, string commandText)
{
// 执行参数为空的方法
return ExecuteScalar(connection, commandType, commandText, (SqlParameter[])null);
}

/// <summary>
/// 执行指定数据库连接对象的命令,指定参数,返回结果集中的第一行第一列.
/// </summary>
/// <remarks>
/// 示例:
/// int orderCount = (int)ExecuteScalar(conn, CommandType.StoredProcedure, "GetOrderCount", new SqlParameter("@prodid", 24));
/// </remarks>
/// <param name="connection">一个有效的数据库连接对象</param>
/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>
/// <param name="commandText">存储过程名称或T-SQL语句</param>
/// <param name="commandParameters">分配给命令的SqlParamter参数数组</param>
/// <returns>返回结果集中的第一行第一列</returns>
public static object ExecuteScalar(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
{
if( connection == null ) throw new ArgumentNullException( "connection" );

// 创建SqlCommand命令,并进行预处理
SqlCommand cmd = new SqlCommand();

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

// 执行SqlCommand命令,并返回结果.
object retval = cmd.ExecuteScalar();

// 清除参数,以便再次使用.
cmd.Parameters.Clear();

if( mustCloseConnection )
connection.Close();

return retval;
}

/// <summary>
/// 执行指定数据库连接对象的命令,指定参数值,返回结果集中的第一行第一列.
/// </summary>
/// <remarks>
/// 此方法不提供访问存储过程输出参数和返回值参数.
///
/// 示例:
/// int orderCount = (int)ExecuteScalar(conn, "GetOrderCount", 24, 36);
/// </remarks>
/// <param name="connection">一个有效的数据库连接对象</param>
/// <param name="spName">存储过程名称</param>
/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param>
/// <returns>返回结果集中的第一行第一列</returns>
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" );

// 如果有参数值
if ((parameterValues != null) && (parameterValues.Length > 0))
{
// 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()
SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

// 给存储过程参数赋值
AssignParameterValues(commandParameters, parameterValues);

// 调用重载方法
return ExecuteScalar(connection, CommandType.StoredProcedure, spName, commandParameters);
}
else
{
// 没有参数值
return ExecuteScalar(connection, CommandType.StoredProcedure, spName);
}
}

/// <summary>
/// 执行指定数据库事务的命令,返回结果集中的第一行第一列.
/// </summary>
/// <remarks>
/// 示例:
/// int orderCount = (int)ExecuteScalar(trans, CommandType.StoredProcedure, "GetOrderCount");
/// </remarks>
/// <param name="transaction">一个有效的连接事务</param>
/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>
/// <param name="commandText">存储过程名称或T-SQL语句</param>
/// <returns>返回结果集中的第一行第一列</returns>
public static object ExecuteScalar(SqlTransaction transaction, CommandType commandType, string commandText)
{
// 执行参数为空的方法
return ExecuteScalar(transaction, commandType, commandText, (SqlParameter[])null);
}

/// <summary>
/// 执行指定数据库事务的命令,指定参数,返回结果集中的第一行第一列.
/// </summary>
/// <remarks>
/// 示例:
/// int orderCount = (int)ExecuteScalar(trans, CommandType.StoredProcedure, "GetOrderCount", new SqlParameter("@prodid", 24));
/// </remarks>
/// <param name="transaction">一个有效的连接事务</param>
/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>
/// <param name="commandText">存储过程名称或T-SQL语句</param>
/// <param name="commandParameters">分配给命令的SqlParamter参数数组</param>
/// <returns>返回结果集中的第一行第一列</returns>
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" );

// 创建SqlCommand命令,并进行预处理
SqlCommand cmd = new SqlCommand();
bool mustCloseConnection = false;
PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection );

// 执行SqlCommand命令,并返回结果.
object retval = cmd.ExecuteScalar();

// 清除参数,以便再次使用.
cmd.Parameters.Clear();
return retval;
}

/// <summary>
/// 执行指定数据库事务的命令,指定参数值,返回结果集中的第一行第一列.
/// </summary>
/// <remarks>
/// 此方法不提供访问存储过程输出参数和返回值参数.
///
/// 示例:
/// int orderCount = (int)ExecuteScalar(trans, "GetOrderCount", 24, 36);
/// </remarks>
/// <param name="transaction">一个有效的连接事务</param>
/// <param name="spName">存储过程名称</param>
/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param>
/// <returns>返回结果集中的第一行第一列</returns>
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" );

// 如果有参数值
if ((parameterValues != null) && (parameterValues.Length > 0))
{
// PPull the parameters for this stored procedure from the parameter cache ()
SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

// 给存储过程参数赋值
AssignParameterValues(commandParameters, parameterValues);

// 调用重载方法
return ExecuteScalar(transaction, CommandType.StoredProcedure, spName, commandParameters);
}
else
{
// 没有参数值
return ExecuteScalar(transaction, CommandType.StoredProcedure, spName);
}
}

#endregion ExecuteScalar

#region ExecuteXmlReader XML阅读器
/// <summary>
/// 执行指定数据库连接对象的SqlCommand命令,并产生一个XmlReader对象做为结果集返回.
/// </summary>
/// <remarks>
/// 示例:
/// XmlReader r = ExecuteXmlReader(conn, CommandType.StoredProcedure, "GetOrders");
/// </remarks>
/// <param name="connection">一个有效的数据库连接对象</param>
/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>
/// <param name="commandText">存储过程名称或T-SQL语句 using "FOR XML AUTO"</param>
/// <returns>返回XmlReader结果集对象.</returns>
public static XmlReader ExecuteXmlReader(SqlConnection connection, CommandType commandType, string commandText)
{
// 执行参数为空的方法
return ExecuteXmlReader(connection, commandType, commandText, (SqlParameter[])null);
}

/// <summary>
/// 执行指定数据库连接对象的SqlCommand命令,并产生一个XmlReader对象做为结果集返回,指定参数.
/// </summary>
/// <remarks>
/// 示例:
/// XmlReader r = ExecuteXmlReader(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
/// </remarks>
/// <param name="connection">一个有效的数据库连接对象</param>
/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>
/// <param name="commandText">存储过程名称或T-SQL语句 using "FOR XML AUTO"</param>
/// <param name="commandParameters">分配给命令的SqlParamter参数数组</param>
/// <returns>返回XmlReader结果集对象.</returns>
public static XmlReader ExecuteXmlReader(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
{
if( connection == null ) throw new ArgumentNullException( "connection" );

bool mustCloseConnection = false;
// 创建SqlCommand命令,并进行预处理
SqlCommand cmd = new SqlCommand();
try
{
PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection );

// 执行命令
XmlReader retval = cmd.ExecuteXmlReader();

// 清除参数,以便再次使用.
cmd.Parameters.Clear();

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

/// <summary>
/// 执行指定数据库连接对象的SqlCommand命令,并产生一个XmlReader对象做为结果集返回,指定参数值.
/// </summary>
/// <remarks>
/// 此方法不提供访问存储过程输出参数和返回值参数.
///
/// 示例:
/// XmlReader r = ExecuteXmlReader(conn, "GetOrders", 24, 36);
/// </remarks>
/// <param name="connection">一个有效的数据库连接对象</param>
/// <param name="spName">存储过程名称 using "FOR XML AUTO"</param>
/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param>
/// <returns>返回XmlReader结果集对象.</returns>
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" );

// 如果有参数值
if ((parameterValues != null) && (parameterValues.Length > 0))
{
// 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()
SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

// 给存储过程参数赋值
AssignParameterValues(commandParameters, parameterValues);

// 调用重载方法
return ExecuteXmlReader(connection, CommandType.StoredProcedure, spName, commandParameters);
}
else
{
// 没有参数值
return ExecuteXmlReader(connection, CommandType.StoredProcedure, spName);
}
}

/// <summary>
/// 执行指定数据库事务的SqlCommand命令,并产生一个XmlReader对象做为结果集返回.
/// </summary>
/// <remarks>
/// 示例:
/// XmlReader r = ExecuteXmlReader(trans, CommandType.StoredProcedure, "GetOrders");
/// </remarks>
/// <param name="transaction">一个有效的连接事务</param>
/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>
/// <param name="commandText">存储过程名称或T-SQL语句 using "FOR XML AUTO"</param>
/// <returns>返回XmlReader结果集对象.</returns>
public static XmlReader ExecuteXmlReader(SqlTransaction transaction, CommandType commandType, string commandText)
{
// 执行参数为空的方法
return ExecuteXmlReader(transaction, commandType, commandText, (SqlParameter[])null);
}

/// <summary>
/// 执行指定数据库事务的SqlCommand命令,并产生一个XmlReader对象做为结果集返回,指定参数.
/// </summary>
/// <remarks>
/// 示例:
/// XmlReader r = ExecuteXmlReader(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
/// </remarks>
/// <param name="transaction">一个有效的连接事务</param>
/// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>
/// <param name="commandText">存储过程名称或T-SQL语句 using "FOR XML AUTO"</param>
/// <param name="commandParameters">分配给命令的SqlParamter参数数组</param>
/// <returns>返回XmlReader结果集对象.</returns>
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" );

// 创建SqlCommand命令,并进行预处理
SqlCommand cmd = new SqlCommand();
bool mustCloseConnection = false;
PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection );

// 执行命令
XmlReader retval = cmd.ExecuteXmlReader();

// 清除参数,以便再次使用.
cmd.Parameters.Clear();
return retval;
}

/// <summary>
/// 执行指定数据库事务的SqlCommand命令,并产生一个XmlReader对象做为结果集返回,指定参数值.
/// </summary>
/// <remarks>
/// 此方法不提供访问存储过程输出参数和返回值参数.
///
/// 示例:
/// XmlReader r = ExecuteXmlReader(trans, "GetOrders", 24, 36);
/// </remarks>
/// <param name="transaction">一个有效的连接事务</param>
/// <param name="spName">存储过程名称</param>
/// <param name="parameterValues">分配给存储过程输入参数的对象数组</param>
/// <returns>返回一个包含结果集的DataSet.</returns>
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" );

// 如果有参数值
if ((parameterValues != null) && (parameterValues.Length > 0))
{
// 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()
SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

// 给存储过程参数赋值
AssignParameterValues(commandParameters, parameterValues);

// 调用重载方法
return ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
}
else
{
// 没有参数值
return ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName);
}
}

#endregion ExecuteXmlReader 阅读器结束

#region FillDataset 填充数据集
/// <summary>
/// 执行指定数据库连接字符串的命令,映射数据表并填充数据集.
/// </summary>
/// <remarks>
/// 示例:
/// FillDataset(connString