MySql pointers

[astro-cosmo]

Is there a specific reason that emit_pointer_for_null_types option is not available for MySQL? The sql.nullxxx types are very inconvenient.

Setting manual overrides seems to have no effect:

- db_type: "int"
     go_type:
            type: "int"
            pointer: true

[kokoc30]

For the override shown, the missing piece is nullable: true. A db_type override defaults to matching non-nullable columns, so it won't replace the type of a nullable column that would otherwise become sql.NullInt32.

For a nullable, signed MySQL INT, put this under your Go generation settings (v2 configuration):

version: "2"
sql:
  - engine: "mysql"
    schema: "schema.sql"
    queries: "query.sql"
    gen:
      go:
        package: "db"
        out: "db"
        overrides:
          - db_type: "int"
            nullable: true
            go_type:
              type: "int"
              pointer: true

Adapt the paths/package to your existing configuration, then regenerate. The explicit override chooses *int; choose int32 instead if you want to retain the default signed INT width. Unsigned columns need a separate matching override with unsigned: true and an appropriate Go type.

The override documentation explains both nullability matching and pointer. The v1.28.0 generator also checks type, nullability, and unsignedness before falling back to MySQL's default mapping.

The blanket option is named emit_pointers_for_null_types (plural). Its documented support covers PostgreSQL/pgx and SQLite, so it should not be relied on for MySQL. Explicit matching overrides are the available mechanism here; I can't establish the maintainers' design rationale from the option's support list alone.