[Question] How to where other field of collection

[letuananh1873]

I have a collection is manga (_id, title, slug) and chapter

At Chapter Model

$collection = self::raw(function ($collection) use ($manga_slug, $chapter_slug) {
            return $collection->aggregate([
                [
                    '$lookup' => [
                        'as' => 'story',
                        'from' => 'manga',
                        'foreignField' => 'id',
                        'localField' => 'manga',
                    ]
                ],
                [
                    '$match' => [
                        'name' => $chapter_slug
                    ]
                ],

            ]);
});

Result show OK, but I want to where field slug of manga collection. How to do it?

Thank you so much!

[zigzagdev]

@letuananh1873

Hi.

You can’t filter by manga.slug directly until after the $lookup, because slug lives in the joined documents (story). Also, your $lookup likely should join chapters.manga to manga._id (not id), unless you truly have an id field in manga.

Here is a correct approach.

$collection = self::raw(function ($collection) use ($manga_slug, $chapter_slug) {
    return $collection->aggregate([
        ['$match' => ['name' => $chapter_slug]],

        ['$lookup' => [
            'from' => 'manga',
            'localField' => 'manga',
            'foreignField' => '_id',
            'as' => 'story',
        ]],

        ['$unwind' => '$story'],

        ['$match' => ['story.slug' => $manga_slug]],
    ]);
});

Hope this helps.