关于.net C# Sql数据库SQLHelper类实例代码

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

public class SQLHelper
{
//取得数据库连接web.config 中配置
public static readonly string ConnectString = ConfigurationManager.ConnectionStrings[DBString].ConnectionString;

/// <summary>
/// 无事务，数据查询
/// </summary>
/// <param name=cmdType>存储过程或Sql语句</param>
/// <param name=cmdText>存储过程名或Sql语句内容</param>
/// <param name=CommandParams>参数列表</param>
/// <returns></returns>
public static int ExecuteNonQuery(CommandType cmdType, string cmdText, params SqlParameter[] CommandParams)
{
SqlCommand cmd = new SqlCommand();

SqlConnection conn = new SqlConnection(ConnectString);

try
{
PrepareCommand(cmd, conn, null, cmdType, cmdText, CommandParams);
int val = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
return val;
}
catch
{
throw;
}
finally
{
conn.Close();

}

}

/// <summary>
/// 有事务，数据操作类
/// </summary>
/// <param name=trans>事务</param>
/// <param name=cmdType>操作类别 (stored procedure,sql)</param>
/// <param name=cmdText>存储过程名或Sql语句</param>
/// <param name=CommandParams>参数</param>
/// <returns>返回影响的数据行数</returns>
public static int ExecuteNonQuery(SqlTransaction trans, CommandType cmdType, string cmdText, params SqlParameter[] CommandParams)
{

SqlCommand cmd = new SqlCommand();
PrepareCommand(cmd, trans.Connection, trans, cmdType, cmdText, CommandParams);
/*if (cmdType == CommandType.StoredProcedure)
{
cmd.Parameters.Add(@RETURN_VALUE, ).Direction = ParameterDirection.ReturnValue;
cmd.ExecuteNonQuery();

val = (int)cmd.Parameters[@RETURN_VALUE].Value;
}
else
if (cmdType==CommandType.Text)
{
val = cmd.ExecuteNonQuery();
}*/
int val = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();

return val;
}

/// <summary>
/// 返回数据集 DataReader
/// </summary>
/// <param name=cmdType></param>
/// <param name=cmdText></param>
/// <param name=CommandParams></param>
/// <returns></returns>
public static SqlDataReader ExecuteReader(CommandType cmdType, string cmdText, params SqlParameter[] CommandParams)
{
SqlCommand cmd = new SqlCommand();
SqlConnection conn = new SqlConnection(ConnectString);

try
{
PrepareCommand(cmd, conn, null, cmdType, cmdText, CommandParams);
SqlDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
cmd.Parameters.Clear();
return rdr;
}
catch (Exception ex)
{
conn.Close();
// throw new Exception(操作失败！);
throw new Exception(ex.Message);
}
}

/// <summary>
/// 有事务的取数据
/// </summary>
/// <param name=trans></param>
/// <param name=cmdType></param>
/// <param name=cmdText></param>
/// <param name=CommandParams></param>
/// <returns></returns>
public static SqlDataReader ExecuteReader(SqlTransaction trans, CommandType cmdType, string cmdText, params SqlParameter[] CommandParams)
{
SqlCommand cmd = new SqlCommand();
PrepareCommand(cmd, trans.Connection, trans, cmdType, cmdText, CommandParams);
SqlDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
cmd.Parameters.Clear();
return rdr;
}

public static object ExecuteScalar(CommandType cmdType, string cmdText, params SqlParameter[] CommandParams)
{
SqlCommand cmd = new SqlCommand();

SqlConnection conn = new SqlConnection(ConnectString);

try
{
PrepareCommand(cmd, conn, null, cmdType, cmdText, CommandParams);
object val = cmd.ExecuteScalar();
cmd.Parameters.Clear();
return val;
}
catch
{
throw;
}
finally
{
conn.Close();
}

}

public static object ExecuteScalar(SqlTransaction trans, CommandType cmdType, string cmdText, params SqlParameter[] CommandParams)
{
SqlCommand cmd = new SqlCommand();
PrepareCommand(cmd, trans.Connection, trans, cmdType, cmdText, CommandParams);
object val = cmd.ExecuteScalar();
cmd.Parameters.Clear();
return val;

}

/// <summary>
/// 根据Sql语句取得表
/// </summary>
/// <param name=cmdType></param>
/// <param name=cmdText></param>
/// <param name=CommandParams></param>
/// <returns></returns>
public static DataTable ExecuteTable(CommandType cmdType, string cmdText, params SqlParameter[] CommandParams)
{
DataTable temptable = new DataTable();

SqlCommand cmd = new SqlCommand();

SqlConnection conn = new SqlConnection(ConnectString);

try
{
PrepareCommand(cmd, conn, null, cmdType, cmdText, CommandParams);

SqlDataAdapter da = new SqlDataAdapter(cmd);

SqlCommandBuilder scb = new SqlCommandBuilder(da);

da.Fill(temptable);
}
finally
{
conn.Close();
}

return temptable;
}

public static DataTable ExecuteTable(SqlTransaction trans, CommandType cmdType, string cmdText, params SqlParameter[] CommandParams)
{
DataTable temptable = new DataTable();
SqlCommand cmd = new SqlCommand();

PrepareCommand(cmd, trans.Connection, trans, cmdType, cmdText, CommandParams);
SqlDataAdapter da = new SqlDataAdapter(cmd);
SqlCommandBuilder scb = new SqlCommandBuilder(da);
da.Fill(temptable);
cmd.Parameters.Clear();

return temptable;

}

/// <summary>
/// 根据Sql语句或存储过程取得数据
/// </summary>
/// <param name=cmdType></param>
/// <param name=cmdText></param>
/// <param name=CommandParams></param>
/// <returns></returns>
public static DataSet ExecuteDataSet(CommandType cmdType, string cmdText, params SqlParameter[] CommandParams)
{
SqlConnection conn = new SqlConnection(ConnectString);

SqlCommand cmd = new SqlCommand();

DataSet TempDataSet = new DataSet();

try
{
PrepareCommand(cmd, conn, null, cmdType, cmdText, CommandParams);
SqlDataAdapter sqlAdapter = new SqlDataAdapter(cmd);
sqlAdapter.Fill(TempDataSet);
cmd.Parameters.Clear();
return TempDataSet;

}
finally
{
conn.Close();
}

}

public static DataSet ExecuteDataSet(SqlTransaction trans, CommandType cmdType, string cmdText, params SqlParameter[] CommandParams)
{
SqlCommand cmd = new SqlCommand();
DataSet TempDataSet = new DataSet();
PrepareCommand(cmd, trans.Connection, trans, cmdType, cmdText, CommandParams);
SqlDataAdapter sqlAdapter = new SqlDataAdapter(cmd);
sqlAdapter.Fill(TempDataSet);
cmd.Parameters.Clear();
return TempDataSet;
}

/// <summary>
/// 生成Sql语句或准备
/// </summary>
/// <param name=cmd></param>
/// <param name=conn></param>
/// <param name=trans></param>
/// <param name=cmdType></param>
/// <param name=cmdText></param>
/// <param name=cmdParms></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);
}
}

public static object ToDBValue(object value)
{
return value == null ? DBNull.Value : value;
}

public static object FromDBValue(object dbValue)
{
return dbValue == DBNull.Value ? null : dbValue;
}
}