using "postgresql.ARRAY(Unicode())" breaks automigrations

[sqlalchemy-bot]

Migrated issue, originally created by Domen Kožar (@iElectric)

Because Unicode is undefined, alembic expects:

postgresql.ARRAY(sa.Unicode())

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

we'd have to run type repr() generation through impl-specific hooks on this one, since a simple concatenation is not going to cut it in this case...

[sqlalchemy-bot]

Changes by Michael Bayer (@zzzeek):

• added labels: postgresql typing issues

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

Issue #215 was marked as a duplicate of this issue.

[sqlalchemy-bot]

Adam Gradzki wrote:

when I have a model with ARRAY(TEXT), alembic incorrectly fails to expand TEXT to sa.TEXT()

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

Issue #303 was marked as a duplicate of this issue.

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

Issue #368 was marked as a duplicate of this issue.

[sqlalchemy-bot]

Andrei Mukhametvaleev (@Mukhametvaleev) wrote:

This is not fixed yet? I have a same problem with some other field types in "postgresql.ARRAY()"

[sqlalchemy-bot]

Stavros Filargyropoulos (@sfilargi) wrote:

Same here on postgresql.ARRAY() with String() vs sa.String()

[sqlalchemy-bot]

Andy Gan (@skavie) wrote:

Same here on postgresql.JSON(astext_type=Text()) vs postgresql.JSON(astext_type=sa.Text())

Thanks Michael.

[sqlalchemy-bot]

aleksanb-td wrote:

I encountered this bug in my project at work yesterday, and after a deep dive in the code i managed to find the correct search terms to find this issue.

Relevant links for future people arriving in this issue tracker:
http://disq.us/p/1df9tlt
http://stackoverflow.com/questions/39997252/flask-python-manage-py-db-upgrade-raise-error
.

There are two solutions for the concrete case with postgresql.JSON(astext_type=Text()) as shown in the stack overflow link. Either remove the astext annotation from the migration manually, as it's actually a default value, secondly add the missing import manually.

A third option is fixing the source itself, which will require changing the _repr_ function called from here https://bitbucket.org/zzzeek/alembic/src/3926ac6b000ed7f3dbdb5376a54f39351b3b4e35/alembic/autogenerate/render.py?at=master&fileviewer=file-view-default#render.py-355.

I tried looking at changing it myself, but without full architectural knowledge it would be a hack at best.

[sqlalchemy-bot]

Paul Brackin (@pbrackin) wrote:

Had this with Integer type:

db.Column( postgresql.ARRAY(db.Integer) )
'''
op.add_column('post', sa.Column('post_path', postgresql.ARRAY(Integer()), nullable=True))
NameError: name 'Integer' is not defined
'''

Patched it by editing the migration file, manually adding 'sa' like so:

op.add_column('post', sa.Column('path', postgresql.ARRAY(Integer()), nullable=True))
#becomes
op.add_column('post', sa.Column('path', postgresql.ARRAY(sa.Integer()), nullable=True))

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

5 years, 16 watchers, 10 votes, zero pull requests :(.

Here is what "impl-specific hook" means:

1. go into autogen/render.py

2. go into def _repr_type. right below where it checks for a _user_defined_render(), we do another check, just like that, against the "impl", which is the thing in alembic/ddl/impl.py -> DefaultImpl. With Postgresql it's an alembic.ddl.postgresql.PostgresqlImpl. In _repr_type, this object is right there at autogen_context.migration_context.impl. if it returns False, keep going. If it returns a string, use it.

3. DefaultImpl gets a new method _render_type(type_obj, autogen_context) that returns False.

4. PosgresqlImpl gets a new method _render_type(type_obj, autogen_context) that looks for ARRAY and then makes the string. Make sure it consults autogen_context.opts['sqlalchemy_module_prefix'] too.

5. new test is added in test_autogen_render.py -> AutogenRenderTest. Look at test_repr_dialect_type for a general dialect-specific type test.

6. run the test to make sure it works!

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

see also #411. We have a PR at zzzeek/alembic#38 which does the above architecture very nicely and I have to pull it into gerrit and get it ready to go. JSON/JSONB should also be pulled into it for #411.

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

Fix postgresql automigration for ARRAY types

Adds a new codepath into render._repr_type() that will consult
the dialect impl for specific types. On the postgresql side,
the exisiting repr() is combined with a replace featuring
the full autogen render of the nested type.

Co-authored-by: Mike Bayer mike_mp@zzzcomputing.com
Fixes: #85
Change-Id: I8796bfeea27d48e6f8bb5ea4562bdc04961ba0d5
Pull-request: zzzeek/alembic#38

→ f1cf86e

[sqlalchemy-bot]

Changes by Michael Bayer (@zzzeek):

• changed status to closed