<?php
    $conn   =   mysql_connect("localhost", "root", "123456") or exit("连接数据库失败！");
      
    mysql_select_db("mysql") or die("选择数据库失败！");
      
    $result =   mysql_query("select * from table");
    if(!$result){
        echo "SQL语句执行失败！";
          
        exit;
    }
?>