Is there anyway to load a child's relationship as a relation in the parent?

[scajal]

I have the following scenario:

orders
    id - integer

coins
    id - integer

order_lines
    id - integer
    type - string
    order_id - integer
    coin_id - integer    

Is there any way I can load the coin of a line as a relation in the orders? The idea is to do $order->coin() (similar to what hasOneThrough does).
I'd also need to filter the lines from which i'd get the coin, for example, get the coin from the first line with type "A" ($order->coinA()).
I want it to be a relationship since I need it to be lazy loaded.

Thanks!

[henzeb]

See hasManyThrough https://laravel.com/docs/10.x/eloquent-relationships#has-many-through

[henzeb]

Yes, you can chain any query builder methods to filter out anything you don't want.

[scajal]

Yes, but the filters will be applied to the last model (in this case, the coin), not to the intermediate model, which is what I need.

[henzeb]

You need to specify the table name in your where clause. Where('order_lines.type', 'A').

[scajal]

Not working. Laravel uses the connection field in Coin, not in OrderLine.

[Angel5a]

Define auxiliary relation coinA in order_lines model, and use it as a thru path.