//---- SqlHelper- -主角要出场了- -怎么说呢下面的这个我看还不错哈
CreateCommand创建命令
#region CreateCommand创建命令
/**//// /// 创建一个由存储过程提供的命令 /// /// /// e.g.: /// SqlCommand command = CreateCommand(conn, "AddCustomer", "CustomerID", "CustomerName"); /// /// /// /// 
/// internal static SqlCommand CreateCommand(SqlConnection connection, string spName, params string[] sourceColumns) 
{ if (connection == null) throw new ArgumentException("connection"); if (spName == null || spName.Length == 0) throw new ArgumentException("spName"); //创建一个命令 SqlCommand cmd = new SqlCommand(spName, connection); cmd.CommandType = CommandType.StoredProcedure; //如果接受一个参数，则处理它 if ((sourceColumns != null) && (sourceColumns.Length > 0)) { //提取存储过程参数 SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName); //设置源列的名称 for (int index = 0; index < sourceColumns.Length; index++) commandParameters[index].SourceColumn = sourceColumns[index]; //将参数附加到命令上 AttachParameters(cmd, commandParameters); } return cmd; }
#endregion
/**/
/// /// 这个方法将一个数组的值赋值到一个SqlParameter数组 /// /// /// 
private
static
void
AssignParameterValues(SqlParameter[] commandParameters,
object
[] parameterValues)
{ if ((commandParameters == null) || parameterValues == null) { //如果没有数据则返回 return; } //参数的数量必须与值得数量匹配 if (commandParameters.Length != parameterValues.Length) { throw new ArgumentException("参数的个数不能匹配参数值的个数"); } //迭代参数数组，把object数组的值赋给相应的参数 for (int i = 0, j = commandParameters.Length; i < j; i++) { //如果数组的值继承自IDbDataParameter,这是赋给它的属性值 if (parameterValues[i] is IDbDataParameter) { IDbDataParameter paraInstance = (IDbDataParameter)parameterValues[i]; if (paraInstance.Value == null) { commandParameters[i].Value = DBNull.Value; } else { commandParameters[i].Value = paraInstance.Value; } } else if (parameterValues[i] == null) { commandParameters[i].Value = DBNull.Value; } else { commandParameters[i].Value = parameterValues[i]; } } }
//--上面的这个也不错，--其他的我也分析清楚了但是感觉一个晕为什么呢~~这个类的重载好多阿，- -不太喜欢故而不写出来- -
SqlHelperParameterCache- -一般就不要用了，浪费内存但是某些特殊情况不如，自动生成数据实体的时候- -瓦塞塞，好用级了，- -可以通过这家伙生成所有存储过程的实体，- -某些程序就是这么干的- -我们先来看看
/**/
/// /// SqlHelperParameterCache 提供一些函数用来发现存储过程的参数 ///
internal
sealed
class
SqlHelperParameterCache
{ private methods, variables, and constructors#region private methods, variables, and constructors //这个类仅仅提供静态方法，并使用一个私有的构造器来阻止创建一个实例化对象 private SqlHelperParameterCache() { } private static Hashtable paramCache = Hashtable.Synchronized(new Hashtable()); /**//// /// 在运行时发现存储过程 /// /// /// /// /// 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); // 将参数置为DBNull.Value foreach (SqlParameter discoveredParameter in discoveredParameters) { discoveredParameter.Value = DBNull.Value; } return discoveredParameters; } /**//// /// 深度拷贝参数数组 /// /// /// 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 caching functions#region caching functions /**//// /// 将参数数组添加到缓存 /// /// /// /// internal 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; } /**//// /// 从缓存中提取参数 /// /// /// /// internal 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 { //为什么要进行克隆 return CloneParameters(cachedParameters); } } #endregion caching functions Parameter Discovery Functions#region Parameter Discovery Functions /**//// /// 获取存储过程的参数 /// /// /// 这个方法将查询数据库，并将其放置在缓存中 /// /// /// /// internal static SqlParameter[] GetSpParameterSet(string connectionString, string spName) { return GetSpParameterSet(connectionString, spName, false); } /**//// /// 获取存储过程的参数 /// /// /// 这个方法将查询数据库，并将其放置在缓存中 /// /// /// /// /// internal 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); } } /**//// /// 获取存储过程的参数 /// /// /// 这个方法将查询数据库，并将其放置在缓存中 /// /// /// /// internal static SqlParameter[] GetSpParameterSet(SqlConnection connection, string spName) { return GetSpParameterSet(connection, spName, false); } /**//// /// 获取存储过程的参数 /// /// /// 这个方法将查询数据库，并将其放置在缓存中 /// /// /// /// /// 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); } } /**//// /// 这个方法将查询数据库，并将其放置在缓存中 /// /// /// /// /// 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 }
//--如果您认真看的上面有个提问为什么要克隆- -这是利用原型设计模式，克隆一个拷贝然后直接用，如果您是用来做存储过程的实体~~就不必克隆了--省内存
//--接下来改写下- -原创阿
using
System;
using
System.Data;
using
System.Configuration;
using
System.Web;
using
System.Web.Security;
using
System.Web.UI;
using
System.Web.UI.WebControls;
using
System.Web.UI.WebControls.WebParts;
using
System.Web.UI.HtmlControls;
using
System.Data.SqlClient;
namespace
Ajaxren
{ /**//// /// 缓存参数用的 /// public class SqlParametersCache : System.Collections.Generic.Dictionary<string, SqlParameter[]> { public static SqlParametersCache t = new SqlParametersCache(); //--单例构造模式 SqlParametersCache() { } /**//// /// 返回对象的实例----因为本例是单例构造模式 /// public static SqlParametersCache GetSqlParametersContent { get { return t; } } /**//// /// 检索缓冲参数,检索的最终形式为ConnectionString,SqlCommandText /// /// /// /// /// public SqlParameter[] GetCatchSqlParameter(string ConnectionString, string SqlCommandText, bool includeReturnValueParameter) { string c = ""; if (ConnectionString == null) throw new ArgumentNullException("请输入你的连接字符串"); if (SqlCommandText == null || SqlCommandText.Length == 0) throw new ArgumentNullException("请输入你的存储过程名字"); //--检查集合里面是否有指定数据 if (this.ContainsKey(ConnectionString + ":" + SqlCommandText) != false) { //--有数据的是在返回的时候在判断this[ConnectionString + ":" + SqlCommandText]key里面包含的数据如果不存在--调用this.GoToSqlSererSelectParameter在次找到该数据 if (this[ConnectionString + ":" + SqlCommandText] == null) { //--再次缓冲这个对象咯~~-调用this.GoToSqlSererSelectParameter找到参数 this[ConnectionString + ":" + SqlCommandText] = this.GoToSqlSererSelectParameter(ConnectionString, SqlCommandText, includeReturnValueParameter); } //--返回数据 return Cps(this[ConnectionString + ":" + SqlCommandText]); } else//-不存在再次缓冲-----key--------------------------------------value-调用this.GoToSqlSererSelectParameter找到参数 this.Add(ConnectionString + ":" + SqlCommandText, this.GoToSqlSererSelectParameter(ConnectionString, SqlCommandText, includeReturnValueParameter)); return this[ConnectionString + ":" + SqlCommandText]; } /**//// /// 去Sql中检索存储过程的参数 /// /// /// /// private SqlParameter[] GoToSqlSererSelectParameter(string ConnectionString, string SqlCommandText, bool includeReturnValueParameter) { SqlConnection BugConnection = new SqlConnection(ConnectionString); SqlCommand BugCommand = new SqlCommand(SqlCommandText, BugConnection); try { BugCommand.CommandType = CommandType.StoredProcedure; BugConnection.Open(); //----反向去SqlServer-找到参数----写入到--BugCommand里面 SqlCommandBuilder.DeriveParameters(BugCommand); } catch (SqlException) { } finally { BugConnection.Close(); } //---false不保存删除第一个参数--这个参数是ParameterDirection.ReturnValue类型 if (!includeReturnValueParameter) { if (BugCommand.Parameters[0].Direction == ParameterDirection.ReturnValue) { BugCommand.Parameters.RemoveAt(0); } } //--是否包含返回参数 SqlParameter[] discoveredParameters = new SqlParameter[BugCommand.Parameters.Count]; //---将参数拷贝到参数集合中--要拷贝到的参数集合--从指定目标数组索引处开始 BugCommand.Parameters.CopyTo(discoveredParameters, 0); // Init the parameters with a DBNull value--将对象复空值 foreach (SqlParameter discoveredParameter in discoveredParameters) { try { discoveredParameter.Value = DBNull.Value; } catch (System.Exception) { } } return Cps(discoveredParameters); } //--作用创建对象的副本 private static SqlParameter[] Cps(SqlParameter[] originalParameters) { SqlParameter[] clonedParameters = new SqlParameter[originalParameters.Length]; for (int i = 0, j = originalParameters.Length; i < j; i++) { //----复制构造函数，以便使用当前实例的值初始化Parameter 类的新实例。 clonedParameters[i] = (SqlParameter)((ICloneable)originalParameters[i]).Clone(); } return clonedParameters; } }}