typesense

If I have an `inventory` collection which has a `product_id` field that references an `id` in a `products` collection, is there a way to formulate a join query that searches `products` and returns only the items that are referenced in the `inventory` collection?

Yes, you can specify
```collection: products
q: query
filter_by: $inventory(id: *)```

Just curious, can you please break down what this query does? I'm wondering why we do `$inventory(id: *)` and not `$inventory(productId: *)`

`id: *` filter matches all the documents of a collection. No other field has an equivalent mechanism. So with `$inventory(id: *)` we do an "inner join" of the `product` documents that matched the query and all of the `inventory` documents.