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

namespace DAL{public class SqlHelper    {//连接字符       public static string sqlconnstring = ConfigurationManager.ConnectionStrings["conn"].ConnectionString;

#region 一个已经连接等待使用的对象/// <summary>/// 创建一个连接好并等待使用的对象/// </summary>/// <param name="conn">连接字符串</param>/// <param name="cmd">已经建立的SqlCommand对象</param>/// <param name="cmdType">连接类型（存储过程还是字符串）</param>/// <param name="sqlText">存储过程名或者SQL语句</param>/// <param name="parms">参数列表</param>       public static void PrepareCommand(SqlConnection conn, SqlCommand cmd, CommandType cmdType, string sqlText, SqlParameter[] parms)       {//判断数据库的连接状态           if (conn.State != ConnectionState.Open)           {               conn.Open();           }           cmd.Connection = conn;//传递连接字符串           cmd.CommandText = sqlText;//存储过程名或者SQL语句           cmd.CommandType = cmdType;//连接类型

if (parms != null)//如果参数列表不为空           {foreach (var item in parms)               {                   cmd.Parameters.Add(item);               }           }

       } #endregion

#region ExecuteNonQuery/// <summary>/// 执行一个返回影响行数的SQLCommand命令/// </summary>/// <param name="connentionstring">连接字符串</param>/// <param name="cmdType">命令类型（存储过程，Sql语句）</param>/// <param name="sqlText">存储过程名称，或者Sql语句</param>/// <param name="parms">参数列表</param>/// <returns>返回数据库中受到影响的行数</returns>       public static int ExecuteNonQuery(string connentionstring, CommandType cmdType, string sqlText, SqlParameter[] parms)       {           SqlCommand cmd = new SqlCommand();try           {using (SqlConnection conn = new SqlConnection(connentionstring))               {                   PrepareCommand(conn, cmd, cmdType, sqlText, parms);int value = cmd.ExecuteNonQuery();return value;               }           }catch (Exception e)           {throw e;           }       } #endregion

#region ExecuteReader/// <summary>/// 一个顺序只读的SqlCommand对象/// </summary>/// <param name="connectionString">连接字符串</param>/// <param name="cmdType">连接类型（存储过程，或者SQL语句）</param>/// <param name="sqlText">存储过程名或者SQL语句</param>/// <param name="parms">数组话的参数列表</param>/// <returns>返回 一个SqlDataReader类型的结果集</returns>       public static SqlDataReader ExecuteReader(string connectionString, CommandType cmdType, string sqlText, SqlParameter[] parms)       {               SqlCommand cmd = new SqlCommand();               SqlConnection conn = new SqlConnection(connectionString);try           {               PrepareCommand(conn, cmd, cmdType, sqlText, parms);               SqlDataReader sdr = cmd.ExecuteReader();return sdr;           }catch            {               conn.Close();throw;           }       } #endregion

#region ExecuteScalar/// <summary>/// 执行一个返还第一行第一列的SqlCommand/// </summary>/// <param name="connectionString">连接字符串</param>/// <param name="cmdtype">连接类型（存储过程，SQL语句）</param>/// <param name="sqltext">存储过程名或者需要执行的SQL语句</param>/// <param name="parms">参数列表</param>/// <returns>返还一个Object 类型的值，使用过程中需要做类型转换</returns>       public static object ExecuteScalar(string connectionString, CommandType cmdtype, string sqltext, SqlParameter[] parms)       {           SqlCommand cmd = new SqlCommand();using (SqlConnection conn = new SqlConnection(connectionString))            {                PrepareCommand(conn, cmd, cmdtype, sqltext, parms);                Object obj = cmd.ExecuteScalar();return obj;            }       } #endregion

#region ExecuteDataset/// <summary>/// 执行一个返回DataSet集/// </summary>/// <param name="connectionString">连接字符串</param>/// <param name="cmdType">连接类型（存储过程，SQL语句）</param>/// <param name="sqltext">需要执行的SQL语句或存储过程名</param>/// <param name="parms">参数列表</param>/// <returns>返回一个DataSet集</returns>       public static DataSet ExecuteDataset(string connectionString, CommandType cmdType, string sqltext, SqlParameter[] parms)       {           SqlCommand cmd = new SqlCommand();using (SqlConnection conn = new SqlConnection(connectionString))           {               PrepareCommand(conn, cmd, cmdType, sqltext, parms);using (SqlDataAdapter sda = new SqlDataAdapter(cmd))               {                   DataSet ds = new DataSet();                   sda.Fill(ds);return ds;               }           }       }#endregion

   }}