Visual中SqlHelper的书写

1 using System;2 using System.Collections.Generic;3 using System.Linq;4 using System.Text;5 using System.Data;6 using System.Data.SqlClient;7 using System.Configuration;

插入引用

1 public static string strconn = ConfigurationManager.ConnectionStrings["TestConnectionString"].ConnectionString;

用于获取链接字符串

public static DataTable Cha(string sql)  {   DataTable table = new DataTable();   SqlDataAdapter sda = new SqlDataAdapter(sql, strconn);   sda.Fill(table);   return table;  }

用于查询数据的方法

public static int ZSG(string sql)  {   int num = 0;   SqlConnection conn = new SqlConnection(strconn);   SqlCommand cmd = new SqlCommand(sql, conn);   conn.Open();   num = cmd.ExecuteNonQuery();   if (conn.State == ConnectionState.Open)   {    conn.Close();   }   return num;  }

用于增加新数据，删除数据，修改数据

Visual中SqlHelper的书写