php连接数据库类（后续再加）

<?php $dsn = ‘mysql:dbname=test;host=127.0.0.1‘; $user = ‘root‘; $password = ‘12345678‘; $dbh = new PDO($dsn, $user, $password); if(!$dbh){ exit(‘连接数据库失败‘); } $context = $dbh->query("select * from my_test"); $res = $context->fetchAll(PDO::FETCH_ASSOC); var_dump($res); $count = $dbh->exec("delete from `my_test` where my_id<150");