Mongolid Cursor

In MongoDB, a cursor is used to iterate through the results of a database query. For example, to query the database and see all results:

Query database

    $cursor = User::where(['kind' => 'visitor']);

In the above example, the $cursor variable will be a Mongolid\Cursor\Cursor.

The Mongolid's Cursor wraps the original MongoDB\Driver\Cursor object of the new MongoDB Driver in a way that you can build queries in a more fluent and easy way. Also, the Mongolid's Cursor will make sure to return the instances of your model instead of stdClass or arrays.

info

The Cursor class of the new driver is not as user-friendly as the old one. Mongolid's cursor also make it as easy to use as the old one.

The Mongolid\Cursor\Cursor object has a lot of methods that helps you to iterate, refine and get information. For example:

Using cursor

    $cursor = User::where(['kind'=>'visitor']);
    
    // Sorts the results by given fields. In the example bellow, it sorts by username DESC
    $cursor->sort(['username'=>-1]);
    
    // Limits the number of results returned.
    $cursor->limit(10);
    
    // Skips a number of results. Good for pagination
    $cursor->skip(20);
    
    // Checks if the cursor is reading a valid result.
    $cursor->valid();
    
    // Returns the first result
    $cursor->first();

You can also chain some methods:

Chaining methods

    $page = 2;
    
    // In order to display 10 results per page
    $cursor = User::all()->sort(['_id'=>1])->skip(10 * $page)->limit(10);
    
    // Then iterate through it
    foreach($cursor as $user) {
        // do something
    }