<?php

try{

        //1. pdo的错误模式，抛出异常，不记录到php的error日志，不影响代码继续运行,

        $opts=array(

                PDO::ATTR_ERRMODE               => PDO::ERRMODE_EXCEPTION,

        );  

        $pdo=new PDO("mysql:host=localhost;dbname=pan","root","xxxx",$opts);

        $pdo->query('set names utf8');

        $sth=$pdo->prepare("select sleep(20) from texts where title like '%测试%'");

        $sth->execute(array("title"=>"测试"));

        $res=$sth->fetchAll(PDO::FETCH_ASSOC);

        print_r($res);

}catch(Exception $e){

        //2. code不是整型，如果不进行处理，会在此处报Fatal的500错误

        //Fatal error: Uncaught Error: Wrong parameters for MyDbException([string $message [, long $code [, Throwable $previous = NULL]]])

        throw new MyDbException($e->getMessage(),intval($e->getCode()));

}

class MyDbException extends Exception{

}

echo "1111111";

/*

3.测试慢查询

        3.1 sql语句中使用 select sleep(20) from

        3.2 开启慢查询日志：

                配置文件：/etc/mysql/mysql.conf.d/mysqld.cnf

                slow_query_log = ON

                slow_query_log_file = /usr/local/mysql/data/slow.log

                long_query_time = 1

                show variables like 'slow_query%';

                show variables like 'long_query_time';

        3.3 kill掉mysql的连接线程

                show full processlist;

                kill id号

*/