mysql_select_db失败

Question

我正在使用phpMyAdmin + MySQL.

我创建了一个数据库,现在正在尝试在PHP脚本中建立连接.奇怪的是连接到数据库工作,所以我得到"连接到MySQL服务器"的消息,但是当我选择'petfood'数据库时,脚本显示"DIED at selection".

知道为什么吗？谢谢,这是我的代码:

<?php

$user = 'localhost';
$pass = 'password';
$db_name = 'petfood';

$db_conn = new mysqli("localhost", $user, $pass, $db_name) or die("Cannot connect to DB");
echo "Connected to MySQL server";
mysql_select_db($db_name) or die("DIED at selection");
echo "Database Selected";

?>

Answer 1

指出不同:

$db_conn = new mysqli("localhost", $user, $pass, $db_name) or die("Cannot connect to DB");
                    ^----

mysql_select_db($db_name) or die("DIED at selection");
     ^---

如果你有适当的调试,你会被告知这个问题:

mysql_select_db($db_name) or die(mysql_error());
                                 ^^^^^^^^^^^^^^

当您可以让系统告诉您错误时,切勿输出固定(无用)错误消息.