更新已弃用的 mysql_connect() [重复]

Question

我有以下 php 代码将我的数据库与 mysql_connect() 连接起来，但我不断收到以下警告：

不推荐使用：mysql_connect()：不推荐使用 mysql 扩展，并且 将来会被移除：使用mysqli或PDO代替.....

更新此连接的正确方法是什么，这样我以后就不会遇到任何问题？

<?php
//CREATED BY ...
/*
1: "die()" will exit the script and show an error statement if something goes wrong
2: A "mysql_connect()" error usually means your username/password are wrong
3. A "mysql_select_db()" error usually means the database does not exist
*/
//Place db host name. Sometimes "localhost" but
//sometimes looks like this: >> ???mysql??.someserver.net
$db_host = "localhost";
//Place the username for the MySQL database here
$db_username = "...";
//Place the password here:
$db_pass = "...";
//Place the name for the MyS
$db_name = "...";

//Run the connection right here!
mysqli_connect("$db_host","$db_username","$db_pass") or die ("could not connect");
mysql_select_db("$db_name") or die("no databases");
?>

编辑：突出显示错误一目了然。

Answer 1

try {
    $dbh = new PDO("mysql:dbname=$db_name;host=$db_host", $db_username, $db_pass);
} catch (PDOException $e) {
    echo 'Connection failed: ' . $e->getMessage();
}

更多信息请看这里http://php.net/manual/de/pdo.prepare.php