[BUG] PK not set properly when creating a record w/ a hasOne relationship

[nickschot]

• Platform: macOS 10.14
• Database: postgres 9.6
• Lux Version: 1.2.3
• Node Version: 11

Having two models with a hasOne <-> belongsTo relationship, when creating the model which has the hasOne side two queries are run:

1. The main INSERT query (which has a returning 'id' statement)
2. An UPDATE query which sets the relationship on the record with the belongsTo side (Created by: https://github.com/postlight/lux/blob/master/src/packages/database/model/index.js#L1229 )

Due to the way the queries are built (and run), the PK is not correctly set on the UPDATE query resulting in a 'nextval(''transactions_id_seq''::regclass)' in Postgres. The newly created PK is only set on the model after the transaction with the queries has completed. See: https://github.com/postlight/lux/blob/master/src/packages/database/model/index.js#L1243 through line 1246.

@zacharygolba it would be great if you could comment on this. I have been debugging lux for a while now, but haven't fully got an idea of how to fix this without fully overhauling the query builder/runner.

PS. #737 is caused by this too.

[nickschot]

Fix is in #737