Union on queries

[GrandChaman]

Hi !

Would'nt it be nice to be able to UNION together more than just SELECT ? Like the returning data from INSERT, UPDATE and DELETE (Postgres only)

Would it mean that the Visitor::visit_union should'nt be provided anymore and implemented at the visitor level ?

[pimeys]

Should not be that hard to implement either. The question is though, what should happen with other databases?

• Runtime error
• Some compilation trick so we wouldn't allow this outside of PostgreSQL
• Emulating the behavior in other databases, a bit like what we do when you write on_conflict(DoNothing) and try to run that on SQL Server.

[GrandChaman]

• IMO runtime error is not good enough
• This seems to be the best solution, using a trait defining that INSERT, UPDATE and DELETE can return some information. This trait would be implemented for SELECT and UNION in all the databases and for every type of query for Postgres
• This seems over complicated and error-prone

[pimeys]

Would you like to give a try for the point two? I know I have quite full schedule on Prisma for the next sprint, so I doubt I have any time to focus in this issue...

[GrandChaman]

Unfortunately, I'll be too busy too :(