What should I do if php5.3 cannot connect to the database?

In the PHP development process, connecting to the database is essential. However, sometimes we may encounter the problem of "php5.3 cannot connect to the database". This is a common error that usually occurs on Apache and MySQL servers installed using XAMPP in Windows environments. So, how to solve this problem?

First of all, we need to know that there may be many reasons for this problem. The most common reason is because PHP5.3 does not support the MySQLi extension, and we need to use the mysqli function in the PHP script to connect to the MySQL database. If you write code like this:

$conn = mysqli_connect($host, $user, $pass, $db);

then you are likely to encounter the problem of "php5.3 cannot connect to the database". The reason is that in PHP5.3, the mysqli library is not enabled by default and needs to be enabled manually.

So, how to open the mysqli library? First, we need to find the PHP.ini file. In XAMPP, this file is located in the xampp\php directory. Open this file and add the following code under "Dynamic Extensions":

;extension=php_mysqli.dll ;extension=php_pdo_mysql.dll

Note that there is a semicolon in front of it, which means commenting out this line of code. We need to remove the preceding semicolon so that these codes can be executed. Alternatively, we can also manually copy the php_mysqli.dll and php_pdo_mysql.dll files to the xampp\php\ext directory, modify the PHP.ini file, and add the following code:

extension=php_mysqli.dll extension=php_pdo_mysql.dll

Save the modified PHP.ini file , close the Apache and MySQL servers in the XAMPP control panel, restart them, and then run the PHP script to successfully connect to the MySQL database.

In addition to the mysqli library not being opened, there may be other reasons that cause the problem of "php5.3 cannot connect to the database". For example, the MySQL server does not start, or the user name, password, host name and other configuration information are incorrect. Therefore, after eliminating the problem that the mysqli library is not opened, we also need to carefully check whether the configuration information is correct and whether the MySQL server has been started.

In short, if you encounter the problem of "php5.3 cannot connect to the database" when using PHP5.3, you can first check whether the mysqli library has been opened. If not, you need to open it manually. If you still cannot connect to the MySQL database after enabling it, you need to carefully check the configuration information and whether the MySQL server has been started. Hope this article can help you solve this problem.

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