<?xml version="1.0" encoding="utf-8" ?>

<configuration>

   <!--连接字符串要添加到connectionStrings标签中-->

  <connectionStrings>

    <!--字符串名字以及内容-->

    <add name="master" connectionString="Data Source=.;Initial Catalog=****; User ID=****;Pwd=****"/>

  </connectionStrings>

    <startup>

        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />

    </startup>

</configuration>

//获取连接字符串
private static readonly string connStr = ConfigurationManager.ConnectionStrings["连接名"].ConnectionString;

/// <summary>

        /// 执行sql语句

        /// </summary>

        /// <param name="sql">sql或存储过程</param>

        /// <param name="type">传入类型 sql语句或存储过程</param>

        /// <param name="ConnectionStrings">连接字符串</param>

        /// <param name="pars"></param>

        /// <returns>查询结果</returns>

        public static DataTable ExecuteDataset(string sql, CommandType type, string ConnectionStrings, params SqlParameter[] pars)

        {

            using (SqlConnection conn = new SqlConnection(ConnectionStrings))

            {

                //打开连接

                conn.Open();

                //设置cmd

                SqlCommand cmd = new SqlCommand();

                //连接字符串

                cmd.Connection = conn;

                //类型  是sql  还是存储过程

                cmd.CommandType = type;

                //内容 sql语句或存储过程

                cmd.CommandText = sql;

                if(pars != null)

                {

                    foreach (SqlParameter parameters in pars)

                    {

                        cmd.Parameters.Add(parameters);

                    }

                }

                using (SqlDataAdapter da = new SqlDataAdapter(cmd))

                {

                    DataTable dt = new DataTable();

                    da.Fill(dt);

                    return dt;

                }

            }

        }