Error parsing generated ALTER COLUMN query

[larkee]

The generated query when calling alter_column is using the PostGres syntax:

ALTER TABLE table_id ALTER COLUMN column_id DROP NOT NULL

However, the Spanner way of doing this would be:

ALTER TABLE table_id ALTER COLUMN column_id column_type [null_constraint]

e.g. to remove NOT NULL

ALTER TABLE Venue ALTER COLUMN LastUpdateTime TIMESTAMP

e.g. to add NOT NULL

ALTER TABLE Venue ALTER COLUMN LastUpdateTime TIMESTAMP NOT NULL

See #118 (comment) for original example and error.

[geudrik]

Original report below for posterity as well

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I think there are some additional bugs here / this successive issue should block #119

Error parsing Spanner DDL statement: ALTER TABLE ttp_mitre_enterprise ALTER COLUMN parent_id DROP NOT NULL

This is the alembic error I get using this branch trying to run a migration. In this case, the alembic migration is attempting to execute the following alembic code - altering a column and dropping the NOT NULL constraint

op.alter_column('ttp_mitre_enterprise', 'parent_id',
               existing_type=sa.String(length=2621440),
               nullable=True)

[geudrik]

@IlyaFaer any update on this?

[IlyaFaer]

Looks like it's related to the Alembic API, not directly the SQLAlchemy dialect. Still, I see we're not the only one who have this problem - there is a solution already. Mimicking it in our API...

[geudrik]

@larkee we good for primetime? :D