Winform下的数据库操作类

  <appSettings>
    <add key="connectionstring" value="server=192.168.0.119;uid=sa;pwd=sa;database=ZhanBan"/>
  </appSettings>

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

namespace DBUtility
{
    public class SqlHelper
    {
        public SqlHelper() 
        { 
        }
        private static string ConnectString = System.Configuration.ConfigurationManager.AppSettings["connectionstring"];
        public void ExecuteNonQuery(string sql)//执行sql语句    
        {
            using (SqlConnection myconn = new SqlConnection(ConnectString))
            {
                myconn.Open();
                SqlCommand mycmd = new SqlCommand(sql, myconn);
                mycmd.ExecuteNonQuery();
            }
        }
        public int ExecutePro(string proname, SqlParameter[] parameters)
        {
          using(SqlConnection myconn = new SqlConnection(ConnectString)) 
          {  
                myconn.Open();
                SqlCommand mycmd = new SqlCommand(proname, myconn);
                mycmd.CommandType = CommandType.StoredProcedure;
                mycmd.CommandText = proname;
            if (parameters != null)
            {
                foreach (SqlParameter parameter in parameters)
                {
                    mycmd.Parameters.Add(parameter);
                }
            }
                return mycmd.ExecuteNonQuery();
          }
        }
        public DataTable ExecuteGetDT(string sql) 
        {
            using(SqlConnection myconn = new SqlConnection(ConnectString))
            {
                myconn.Open();
                SqlCommand mycmd = new SqlCommand(sql, myconn);
                SqlDataAdapter mydata_ad = new SqlDataAdapter(mycmd);
                DataSet ds = new DataSet();
                DataTable dt = new DataTable("table");
                ds.Tables.Add(dt);
                mydata_ad.Fill(ds, "table");
                return dt;
            }
        }

    }

}