Query Events (Query Builder 14)

Query event

The callback of the database operation is also called the query event. It is a callback method designed for the CURD operation of the database. It mainly includes:

##before_selectbefore_findafter_insertafter_updateafter_delete

Event	Description
	select Callback before query
	findCallback before query
	insertCallback after successful operation
	updateCallback after successful operation
	deleteCallback after successful operation

Use the following method to register database query events

\think\facade\Db::event('before_select', function ($query) {
    // 事件处理
    return $result;
});

The same query event can register multiple response executions. Query events have also been taken over by the event system in the new version, so if you register a before_select query event listener, the bottom layer actually registers a listener for the event identified as db.before_select.

There is only one method parameter for query events: the current query object. But you can add additional parameters through dependency injection.