Sequence default fails in migration

[elprans]

Discussed in #3493

^{Originally posted by tchak February 15, 2022}
I have the following schema:

module default {
  scalar type ProjectNumber extending sequence;

  type Project {
    required property number -> ProjectNumber {
      constraint exclusive;
    }
    required property name -> str;
  }
}

I expect number to be autofilled. But when I use this schema from TypeScript driver type signature refuses to let me create a Project without specifying a number property. I tried the following schema but it failed on migration:

module default {
  scalar type ProjectNumber extending sequence;

  type Project {
    required property number -> ProjectNumber {
      constraint exclusive;
      default := sequence_next(introspect ProjectNumber);
    }
    required property name -> str;
  }
}

Is this is a bug or intended behaviour ?

[elprans]

        File "/home/elvis/dev/edgedb/edgedb/edb/pgsql/delta.py", line 3061, in get_pointer_default
          default_value = schemamech.ptr_default_to_col_default(
        File "/home/elvis/dev/edgedb/edgedb/edb/pgsql/schemamech.py", line 417, in ptr_default_to_col_default
          sql_expr = compiler.compile_ir_to_sql_tree(ir, singleton_mode=True)
        File "/home/elvis/dev/edgedb/edgedb/edb/pgsql/compiler/__init__.py", line 129, in compile_ir_to_sql_tree
          raise errors.InternalServerError(*args) from e
      edb.errors.InternalServerError: no IR compiler handler for <class 'edb.ir.ast.TypeIntrospection'>

[tchak]

Thanks for quick answer!
So once the bug is resolved if I want correctly typed behaviour in the query builder I should use the second version of the schema? The documentation makes it sound as if autoincrement behaviour is enabled without explicit default with a call to sequence_next.

[elprans]

Yes, sequence scalars have an implicit default, you don't need to specify it explicitly. The querybuilder needs to be adjusted to be aware of the fact.