Manual:Sql.php

sql.php is a maintenance file which allows performing SQL queries. If you give an SQL file as the first argument, it will replace MediaWiki specific code comments like   for the configured database prefix (among others). If you don't give it a file, then you can query the database in an interactive fashion, similar to the MySQL command line tool.

This script is often used if you want to upgrade MediaWiki, but have a large, master/replica-database setup and don't want any downtime. Instead of using update.php, you might use sql.php to apply database individual patches from   directory on each sql server separately, taking the individual server out of rotation while the schema change runs. Generally you should only do this if you have to - most users should use the update.php script instead.

Example:

Available options for this script from the command line are: