MySqlHelper

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

namespace MySqlHelper
{
    public class SQLHelper
    {
        private static readonly string connstr = ConfigurationManager.ConnectionStrings["connstr"].ConnectionString;
        /// <summary>
        /// 连接数据库
        /// </summary>
        /// <returns></returns>
        public static SqlConnection CreateConnection()
        {
            SqlConnection conn = new SqlConnection(connstr);
            conn.Open();
            return conn;
        }
        /// <summary>
        /// 返回受影响行数
        /// </summary>
        /// <param name="conn"></param>
        /// <param name="sql"></param>
        /// <param name="parameters"></param>
        /// <returns></returns>
        public static int ExecuteNonQuery(SqlConnection conn, string sql, params SqlParameter[] parameters)
        {
            using (SqlCommand cmd = conn.CreateCommand())
            {
                cmd.CommandText = sql;
                cmd.Parameters.AddRange(parameters);
                return cmd.ExecuteNonQuery();
            }
        }
        /// <summary>
        /// 按现有连接，返回受影响行数
        /// </summary>
        /// <param name="sql"></param>
        /// <param name="parameters"></param>
        /// <returns></returns>
        public static int ExecuteNonQuery(string sql, params SqlParameter[] parameters)
        {
            using (SqlConnection conn = CreateConnection())
            {
                return ExecuteNonQuery(conn,sql,parameters);
            }
        }
        /// <summary>
        /// 返回第一行第一条数据
        /// </summary>
        /// <param name="conn"></param>
        /// <param name="sql"></param>
        /// <param name="parameters"></param>
        /// <returns></returns>
        public static object ExecuteScalar(SqlConnection conn, string sql, params SqlParameter[] parameters)
        {
            using (SqlCommand cmd = conn.CreateCommand())
            {
                cmd.CommandText = sql;
                cmd.Parameters.AddRange(parameters);
                return cmd.ExecuteScalar();
            }
        }
        /// <summary>
        /// 按现有连接，返回第一行第一条数据
        /// </summary>
        /// <param name="sql"></param>
        /// <param name="parameters"></param>
        /// <returns></returns>
        public static object ExecuteScalar(string sql, params SqlParameter[] parameters)
        {
            using (SqlConnection conn = CreateConnection())
            {
                return ExecuteScalar(conn,sql,parameters);
            }
        }
        /// <summary>
        /// 返回多条数据
        /// </summary>
        /// <param name="conn"></param>
        /// <param name="sql"></param>
        /// <param name="parameters"></param>
        /// <returns></returns>
        public static DataTable ExecuteReader(SqlConnection conn, string sql, params SqlParameter[] parameters)
        {
            DataTable table = new DataTable();
            using (SqlCommand cmd = conn.CreateCommand())
            {
                cmd.CommandText = sql;
                cmd.Parameters.AddRange(parameters);
                using (SqlDataReader reader = cmd.ExecuteReader())
                {
                    table.Load(reader);
                }
            }
            return table;
        }
        /// <summary>
        /// 按现有连接，返回多条数据
        /// </summary>
        /// <param name="sql"></param>
        /// <param name="parameters"></param>
        /// <returns></returns>
        public static DataTable ExecuteReader(string sql, params SqlParameter[] parameters)
        {
            using (SqlConnection conn = CreateConnection())
            {
                return ExecuteReader(conn,sql,parameters);
            }
        }

    }
}

Web.config配置文件:

<configuration>
    <system.web>
      <compilation debug="true" targetFramework="4.5" />
      <httpRuntime targetFramework="4.5" />
    </system.web>
  <connectionStrings>
    <add name="connstr" connectionString="server=PC-20140729GKIU;user id=sa;password=update123;database=sy"/>
  </connectionStrings>
</configuration>