ADO数据库连接步骤

数据库连接步骤
一、Web.Config文件配置数据库连接字段
<appSettings>
<add key=”ConnectString”value=”SERVER=数据库服务器名称;UID=用户名;PWD=密码;DA TABASE=数据库名称/>”
</appSettings>
二、SQLHelper
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Configuration;
using System.Data.SqlClient;
using System.Data;
namespace DAL
{
public static class SQLHelper
{
private static string strConn = ConfigurationManager.AppSettings["connectString"];
/// <summary>
/// 执行一条SQL语句返回执行结果的行数
/// </summary>
/// <param name="strSQL">SQL语句</param>
/// <returns></returns>
public static int ExecuteSQL(string strSQL)
{
using (SqlConnection conn = new SqlConnection(strConn))//定义Connection 对象
{
using (SqlCommand cmd = new SqlCommand(strSQL, conn))//定义Command对象，并且将Connection连接字段和Connection对象作为参数传递给Command对象
{
try
{
conn.Open();//打开数据
int rows = cmd.ExecuteNonQuery();
return rows;
}
catch (SqlException ex)
{
conn.Close();
throw ex;
}
}
}
}
/// <summary>
/// 执行SQL语句返回数据结果集
/// </summary>
/// <param name="strSQL">SQL语句</param>
/// <returns></returns>
public static DataSet Query(string strSQL)
{
using (SqlConnection conn = new SqlConnection(strConn))
{
DataSet ds = new DataSet();
try
{
conn.Open();
SqlDataAdapter sad = new SqlDataAdapter(strSQL, conn);
sad.Fill(ds, "ds");
return ds;
}
catch (SqlException ex)
{
conn.Close();
throw ex;
}
}
}
}
}}。