Views referencing each other can't be created simultaneously

I can’t seem to create multiple views, where one references a previous view, at the same time.

An minimal example of what I would like to define (at the same time, so both views should be generated within one migration):

first_view = PGView(
    schema="public",
    signature="first_view",
    definition="SELECT * FROM some_table;"
)
second_view = PGView(
    schema="public",
    signature="second_view",
    definition="SELECT * FROM first_view;"
)

I get the following error while trying to autogenerate the alembic migration: psycopg2.errors.UndefinedTable: relation "second_view" does not exist. It seems that while comparing the existing views with the newly defined views, alembic actually attempts to execute the view definition, which fails for the second view as the first view is then not yet defined. https://github.com/olirice/alembic_utils/blob/a4bc7f5f025335faad7b178eb84ab78093e525ec/src/alembic_utils/replaceable_entity.py#L28-L40

[olirice]

Resolved in alembic_utils>=0.3.2

Tested here Not all cases are covered but general use is expected to work

If you end up on this thread and are running into an problem please open a new issue with minimal reproducible example.

[olirice]

Good point, I didn’t consider the rendering step.

At the moment, the only solution would be to manually write the migration as shown ^, or autogenerate a new migration when you want to checkpoint and be able to refer to the new entities like:

• add first_view to source
• autogenerate migration for first_view
• apply the migration
• add second_view to source
• autogenerate migration for second_view