Intelligent Update queries

[pelletencate]

It would be great to have the DSL available in UPDATE queries, so I can assign SQL values to fields.

Something like:

# Inherit all venue's cities and countries from their owners
Venue.joining { owner }.updating { { city: owner.city, country: owner.country } }

# or (less "nice" alternative IMO)
Venue.joining { owner }.updating { [city(owner.city), country(owner.country) }