How do i do a join that doesn't use document key?

SELECT asset.fqdn, FROM port JOIN asset KEY port.assetId

How would I run a query like this:

“SELECT asset.fqdn, FROM bucket asset JOIN bucket port ON port.assetId =” (or could be key).

Asset document is asset:1 and has (asset:1), and some other details.

Port document has port.assetId (asset:1) and some other details.

Trying to get ports associated with the asset without listing all port UUID’s under the asset.