网上找的中文解释的SqlHelper

来源：互联网发布：面向对象编程编辑：程序博客网时间：2024/06/11 11:19

2008-01-12 17:51

//这是在网上找的中文解释的SqlHelper
using System;

using System.Configuration;

using System.Data;

using System.Data.SqlClient;

using System.Collections;

namespace com.DataAccess

{

///

/// SqlHelper类提供很高的数据访问性能,

/// 使用SqlClient类的通用定义.

///

public abstract class SqlHelper

{

//定义数据库连接串

public static readonly string ConnectionStringLocalTransaction = ConfigurationManager.ConnectionStrings["TestConnectionString"].ConnectionString;

//public static readonly string ConnectionStringInventoryDistributedTransaction = ConfigurationManager.ConnectionStrings["SQLConnString2"].ConnectionString;

//public static readonly string ConnectionStringOrderDistributedTransaction = ConfigurationManager.ConnectionStrings["SQLConnString3"].ConnectionString;

//public static readonly string ConnectionStringProfile = ConfigurationManager.ConnectionStrings["SQLProfileConnString"].ConnectionString;

// 存贮Cache缓存的Hashtable集合

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

///

/// 使用连接字符串，执行一个SqlCommand命令（没有记录返回）

/// 使用提供的参数集.

///

/// 示例:

/// int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));

///

/// 一个有效的SqlConnection连接串

/// 命令类型CommandType(stored procedure, text, etc.)

/// 存贮过程名称或是一个T-SQL语句串

/// 执行命令的参数集

/// 受此命令影响的行数

public static int ExecuteNonQuery(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)

{

SqlCommand cmd = new SqlCommand();

using (SqlConnection conn = new SqlConnection(connectionString))

{

PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);

int val = cmd.ExecuteNonQuery();

cmd.Parameters.Clear();

return val;

}

///

/// 在一个存在的连接上执行数据库的命令操作

/// 使用提供的参数集.

///

/// e.g.:

/// int result = ExecuteNonQuery(connection, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));

///

/// 一个存在的数据库连接对象

/// 命令类型CommandType (stored procedure, text, etc.)

/// 存贮过程名称或是一个T-SQL语句串

/// 执行命令的参数集

/// 受此命令影响的行数

public static int ExecuteNonQuery(SqlConnection connection, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)

{

SqlCommand cmd = new SqlCommand();

PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);

int val = cmd.ExecuteNonQuery();

cmd.Parameters.Clear();

return val;

}

///

/// 在一个事务的连接上执行数据库的命令操作

/// 使用提供的参数集.

///

/// e.g.:

/// int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));

///

/// 一个存在的事务

/// 命令类型CommandType (stored procedure, text, etc.)

/// 存贮过程名称或是一个T-SQL语句串

/// 执行命令的参数集

/// 受此命令影响的行数

public static int ExecuteNonQuery(SqlTransaction trans, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)

{

SqlCommand cmd = new SqlCommand();

PrepareCommand(cmd, trans.Connection, trans, cmdType, cmdText, commandParameters);

int val = cmd.ExecuteNonQuery();

cmd.Parameters.Clear();

return val;

}

///

/// 在一个连接串上执行一个命令，返回一个SqlDataReader对象

/// 使用提供的参数.

///

/// e.g.:

/// SqlDataReader r = ExecuteReader(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));

///

/// 一个有效的SqlConnection连接串

/// 命令类型CommandType(stored procedure, text, etc.)

/// 存贮过程名称或是一个T-SQL语句串

/// 执行命令的参数集

/// 一个结果集对象SqlDataReader

public static SqlDataReader ExecuteReader(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)

{

SqlCommand cmd = new SqlCommand();

SqlConnection conn = new SqlConnection(connectionString);

// 如果不存在要查询的对象，则发生异常

// 连接要关闭

// CommandBehavior.CloseConnection在异常时不发生作用

try

{

PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);

SqlDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);

cmd.Parameters.Clear();

return rdr;

}

catch

{

conn.Close();

throw;

}

///

/// 在一个连接串上执行一个命令，返回表中第一行，第一列的值

/// 使用提供的参数.

///

/// e.g.:

/// Object obj = ExecuteScalar(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));

///

/// 一个有效的SqlConnection连接串

/// 命令类型CommandType(stored procedure, text, etc.)

/// 存贮过程名称或是一个T-SQL语句串

/// 执行命令的参数集 /// 返回的对象，在使用时记得类型转换

public static object ExecuteScalar(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)

{

SqlCommand cmd = new SqlCommand();

using (SqlConnection connection = new SqlConnection(connectionString))

{

PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);

object val = cmd.ExecuteScalar();

cmd.Parameters.Clear();

return val;

}

///

/// 在一个连接上执行一个命令，返回表中第一行，第一列的值

/// 使用提供的参数.

///

/// e.g.:

/// Object obj = ExecuteScalar(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));

///

/// 一个有效的SqlConnection连接

/// 命令类型CommandType(stored procedure, text, etc.)

/// 存贮过程名称或是一个T-SQL语句串

/// 执行命令的参数集 /// 返回的对象，在使用时记得类型转换

public static object ExecuteScalar(SqlConnection connection, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)

{

SqlCommand cmd = new SqlCommand();

PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);

object val = cmd.ExecuteScalar();

cmd.Parameters.Clear();

return val;

}

///

/// 在缓存中添加参数数组

///

/// 参数的Key

/// 参数数组

public static void CacheParameters(string cacheKey, params SqlParameter[] commandParameters)

{

parmCache[cacheKey] = commandParameters;

}

///

/// 提取缓存的参数数组

///

/// 查找缓存的key

/// 返回被缓存的参数数组

public static SqlParameter[] GetCachedParameters(string cacheKey)

{

SqlParameter[] cachedParms = (SqlParameter[])parmCache[cacheKey];

if (cachedParms == null)

return null;

SqlParameter[] clonedParms = new SqlParameter[cachedParms.Length];

for (int i = 0, j = cachedParms.Length; i < j; i++)

clonedParms[i] = (SqlParameter)((ICloneable)cachedParms[i]).Clone();

return clonedParms;

}

///

/// 提供一个SqlCommand对象的设置

///

/// SqlCommand对象

/// SqlConnection 对象

/// SqlTransaction 对象

/// CommandType 如存贮过程，T-SQL

/// 存贮过程名或查询串

/// 命令中用到的参数集

private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, CommandType cmdType, string cmdText, SqlParameter[] cmdParms)

{

if (conn.State != ConnectionState.Open)

conn.Open();

cmd.Connection = conn;

cmd.CommandText = cmdText;

if (trans != null)

cmd.Transaction = trans;

cmd.CommandType = cmdType;

if (cmdParms != null)

{

foreach (SqlParameter parm in cmdParms)

cmd.Parameters.Add(parm);

}