Here is a good example of the module:
https://github.com/gr8b/zabbix-module-sqlexplorer

Sometimes it's required to execute SQL directly from Frontend, instead of opening command line tool or other tool to be able to connect to the database.

Also will help in cases, then user who is doing troubleshooting doesn't have full access to the database, but will be able to use Frontend UI to do some SQl.

Also can be added separate user role permissions to execute such SQL in the interface.