Visual中SqlHelper的书写(*)

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

插入引用

private static string strconn = ConfigurationManager.ConnectionStrings["DigitalProductShopConnectionString"].ConnectionString;

获取连接

 public static DataTable ChaXun(string sql)
        {
            using (DataTable dt=new DataTable())
            {
                using (SqlDataAdapter sda=new SqlDataAdapter(sql,strconn))
                {
                    sda.Fill(dt);
                }

                return dt;
            }
        }

查询方法

 public static int FeiChaXun(string sql)
        {
            int i = 0;
            using (SqlConnection conn = new SqlConnection(strconn))
            {
                using (SqlCommand scd = new SqlCommand(sql, conn))
                {
                    try
                    {
                        conn.Open();
                        i = scd.ExecuteNonQuery();
                    }
                    finally
                    {
                        if (conn.State == ConnectionState.Open)
                        {
                            conn.Close();
                        }
                    }
                }
            }
            return i;
        }

增删改方法