SqlHelper类

sqlhelper类
using System;
using System.Collections.Generic;
using System.Text;
using System.Configuration;
using System.Data.SqlClient;
using System.Data;
using System.Collections;

namespace Utility
{
/// <summary>
/// SqlHelper类提供很高的数据访问性能,
/// 使用SqlClient类的通用定义.
/// </summary>
public abstract class SqlHelper
{
//定义数据库连接串
public static readonly string CONN_STRING =
ConfigurationManager.ConnectionStrings[
"connectionString"].ConnectionString;

// 存贮Cache缓存的Hashtable集合
private static Hashtable parmCache = Hashtable.Synchronized(new Hashtable());

/// <summary>
/// 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.
/// </summary>
/// <param name="connectionString">一个有效的SqlConnection连接串</param>
/// <param name="commandType">命令类型CommandType(stored procedure, text, etc.)</param>
/// <param name="commandText">存贮过程名称或是一个T-SQL语句串</param>
/// <param name="commandParameters">执行命令的参数集</param>
/// <returns>受此命令影响的行数</returns>
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;
}
}

/// <summary>
/// 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.
/// </summary>
/// <param name="conn">一个存在的数据库连接对象</param>
/// <param name="commandType">命令类型CommandType (stored procedure, text, etc.)</param>
/// <param name="commandText">存贮过程名称或是一个T-SQL语句串</param>
/// <param name="commandParameters">执行命令的参数集</param>
/// <returns>受此命令影响的行数</returns>
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;

}


/// <summary>
/// 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.
/// </summary>
/// <param name="trans">一个存在的事务</param>
/// <param name="commandType">命令类型CommandType (stored procedure, text, etc.)</param>
/// <param name="commandText">存贮过程名称或是一个T-SQL语句串</param>
/// <param name="commandParameters">执行命令的参数集</param>
/// <returns>受此命令影响的行数</returns>
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;
}

/// <summary>
/// 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.
/// </summary>
/// <param name="connectionString">一个有效的SqlConnection连接串</param>
/// <param name="commandType">命令类型CommandType(stored procedure, text, etc.)</param>
/// <param name="commandText">存贮过程名称或是一个T-SQL语句串</param>
/// <param name="commandParameters">执行命令的参数集</param>
/// <returns>一个结果集对象SqlDataReader</returns>
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;
}
}
/// <summary>
/// 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.
/// </summary>
/// <param name="connectionString">一个有效的SqlConnection连接串</param>
/// <param name="commandType">命令类型CommandType(stored procedure, text, etc.)</param>
/// <param name="commandText">存贮过程名称或是一个T-SQL语句串</param>
/// <param name="commandParameters">执行命令的参数集</param>
/// <returns>返回的对象,在使用时记得类型转换</returns>
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;
}
}



/// <summary>
/// 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.
/// </summary>
/// <param name="connectionString">一个有效的SqlConnection连接</param>
/// <param name="commandType">命令类型CommandType(stored procedure, text, etc.)</param>
/// <param name="commandText">存贮过程名称或是一个T-SQL语句串</param>
/// <param name="commandParameters">执行命令的参数集</param>
/// <returns>返回的对象,在使用时记得类型转换</returns>
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;
}

/// <summary>
/// 在一个连接串上执行一个命令,返回数据集
/// 使用提供的参数.
/// </summary>
/// <param name="connectionString">一个有效的SqlConnection连接串</param>
/// <param name="cmdType">命令类型CommandType(stored procedure, text, etc.)</param>
/// <param name="commandText">存贮过程名称或是一个T-SQL语句串</param>
/// <param name="commandParameters">执行命令的参数集</param>
/// <returns>返回数据集</returns>
public static DataSet ExecuteDataSet(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
{

SqlCommand cmd
= new SqlCommand();

using (SqlConnection conn = new SqlConnection(connectionString))
{
PrepareCommand(cmd, conn,
null, commandType, commandText, commandParameters);

SqlDataAdapter adapter
= new SqlDataAdapter(cmd);
DataSet ds
= new DataSet();
adapter.Fill(ds);

cmd.Parameters.Clear();
return ds;
}
}

/// <summary>
/// 在一个连接串上执行一个命令,返回数据集
/// 使用提供的参数.
/// </summary>
/// <param name="connectionString">一个有效的SqlConnection连接串</param>
/// <param name="cmdType">命令类型CommandType(stored procedure, text, etc.)</param>
/// <param name="commandText">存贮过程名称或是一个T-SQL语句串</param>
/// <param name="commandParameters">执行命令的参数集</param>
/// <returns>返回DataTable</returns>
public static DataTable ExecuteDataTable(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
{

SqlCommand cmd
= new SqlCommand();

using (SqlConnection conn = new SqlConnection(connectionString))
{
PrepareCommand(cmd, conn,
null, commandType, commandText, commandParameters);

SqlDataAdapter adapter
= new SqlDataAdapter(cmd);
DataSet ds
= new DataSet();
adapter.Fill(ds);

cmd.Parameters.Clear();
return ds.Tables[0];
}
}

/// <summary>
/// 在缓存中添加参数数组
/// </summary>
/// <param name="cacheKey">参数的Key</param>
/// <param name="cmdParms">参数数组</param>
public static void CacheParameters(string cacheKey, params SqlParameter[] commandParameters)
{
parmCache[cacheKey]
= commandParameters;
}



/// <summary>
/// 提取缓存的参数数组
/// </summary>
/// <param name="cacheKey">查找缓存的key</param>
/// <returns>返回被缓存的参数数组</returns>
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;
}



/// <summary>
/// 提供一个SqlCommand对象的设置
/// </summary>
/// <param name="cmd">SqlCommand对象</param>
/// <param name="conn">SqlConnection 对象</param>
/// <param name="trans">SqlTransaction 对象</param>
/// <param name="cmdType">CommandType 如存贮过程,T-SQL</param>
/// <param name="cmdText">存贮过程名或查询串</param>
/// <param name="cmdParms">命令中用到的参数集</param>
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);
}
}

/// <summary>
/// 执行多条SQL语句,实现数据库事务。
/// </summary>
/// <param name="SQLStringList">多条SQL语句</param>
public static int ExecuteSqlTran(ArrayList SQLStringList)
{
using (SqlConnection conn = new SqlConnection(CONN_STRING))
{
conn.Open();
SqlCommand cmd
= new SqlCommand();
cmd.Connection
= conn;
SqlTransaction tx
= conn.BeginTransaction();
cmd.Transaction
= tx;
try
{
for (int n = 0; n < SQLStringList.Count; n++)
{
string strsql = SQLStringList[n].ToString();
if (strsql.Trim().Length > 1)
{
cmd.CommandText
= strsql;
cmd.ExecuteNonQuery();
}
}
tx.Commit();
return 1;
}
catch (System.Data.SqlClient.SqlException E)
{
tx.Rollback();
throw new Exception(E.Message);
}
}
}
}
}

 

posted @ 2010-08-19 17:35  疯狂的民工  阅读(218)  评论(0编辑  收藏  举报