检查belongsToMany关系是否存在 - Laravel

Question

Two of my tables (clients and products) have a ManyToMany relation using Laravel's blongToMany and a pivot table. Now I want to check if a certain client has a certain product.

I could create a model to check in the pivot table but since Laravel does not require this model for the belongsToMany method I was wondering if there is another way to check if a certain relationship exists without having a model for the pivot table.

Answer 1

I think the official way to do this is to do:

$client = Client::find(1);
$exists = $client->products->contains($product_id);

It's somewhat wasteful in that it'll do the SELECT query, get all results into a Collection and then finally do a foreach over the Collection to find a model with the ID you pass in. However, it doesn't require modelling the pivot table.

If you don't like the wastefulness of that, you could do it yourself in SQL/Query Builder, which also wouldn't require modelling the table (nor would it require getting the Client model if you don't already have it for other purposes:

$exists = DB::table('client_product')
    ->whereClientId($client_id)
    ->whereProductId($product_id)
    ->count() > 0;