Add a way to tell sqlc to always use nullable type when casting

[quinn]

What do you want to change?

for example:

select null::float8 is a pgtype.Float8. However,

    select CASE WHEN true THEN null
    ELSE 0 END::float8,

is a float64. I'm basically having to do a bunch of weird stuff in sql to get sqlc to give up and codegen an interface{}, which sucks, but at least does not panic. And then I cast it at runtime to the correct type.

What database engines need to be changed?

PostgreSQL

What programming language backends need to be changed?

Go

[snowtoslow]

Hey sir @quinn

In your sqlc.yaml/yml/json file you can add:

      go:
        #other config ommited for brievity
        overrides:
          - db_type: "float8"
            # nullable: true => should not be set, because it causes generation of `float64` idk why btw
            go_type:
              import: 'github.com/jackc/pgx/v5/pgtype'
              type: 'Float8'

Run sqlc generate. Should work 🙈

[quinn]

Hey, well I don't really want to change all floats, i like having the "real" types when sqlc determines it is not nullable. Basically I want to way to tell sqlc that a field in a query is in fact nullable, when it mistakenly things it is not.