Question

我正在使用phpMyAdmin + MySQL。

我创建了一个数据库，现在正尝试在PHP脚本中建立连接。奇怪的是连接到数据库工作，所以我得到了连接到MySQL服务器＆＃34;消息，但我在选择“宠物食品”时说。数据库，脚本显示＆＃34; DIED在选择＆＃34;。

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

发现差异：

$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");
     ^---

如果您进行了适当的调试，您就会被告知问题：

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）的错误消息。

Answer 2

1：使用mysql

$dbhandle = mysql_connect($hostname, $username, $password) or die("Unable to connect to MySQL"); mysql_select_db("examples",$dbhandle) or die("Could not select examples"); $query = "SELECT name FROM mytable" ; $result = mysqli_query($query);

2：使用mysqli

$link = mysqli_connect("myhost","myuser","mypassw","mybd") or die("Error " . mysqli_error($link)); $query = "SELECT name FROM mytable" ; $result = mysqli_query($link, $query);

mysql_select_db失败

2 个答案: