What to do if php mysql connection fails

php mysql connection fails because higher versions of php no longer use "mysql_connect()" to connect to the MySQL database. The solution is to use mysqli or PDO to replace "mysql_connect" and reconnect to mysql.

Recommended: "PHP Tutorial"

PHP cannot connect to MySQL and failed

Higher versions of php no longer use mysql_connect() to connect to the MySQL database.

<?php
$con = mysql_connect("localhost","root","abc123");
if (!$con)
  {
  die(&#39;连接失败&#39; . mysql_error());
  }
?>

Today I used the above code to link to my database, but it failed. Tip me:

Deprecated: mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead in D:\Sian\Blog pages\demo.php on line 2

mysql_connect() has been deprecated and will be deleted in the future. Use mysqli or PDO to replace it.

Then the PHP official website explains it this way:

mysql_connect - Open a connection to the MySQL server

Warning

This extension is available since PHP 5.5.0 Deprecated and removed starting with PHP 7.0.0. It should be replaced with the MySQLi or PDO_MySQL extension. See the MySQL: Selection API guide and related FAQ for more information.

The alternatives to this function are:

mysqli_connect()
PDO::__construct()

The above is the detailed content of What to do if php mysql connection fails. For more information, please follow other related articles on the PHP Chinese website!