autogenerate wants to add existing named index

[sqlalchemy-bot]

Migrated issue, originally created by dan milon (@danmilon)

I've got the following index

Index(EMAIL_UNIQUE_CONSTRAINT_NAME, func.lower(email), unique=True)

and even though it already exists in the database, a new revision tries to create it again.

op.create_index('user_email_unique', 'user', [sa.text('lower("user".email)')], unique=True)

I think autogenerate is able to catch these kind of indexes. Am I doing something wrong?

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

can you please share:

1. the target database in use (mysql, Postgresql, etc.)

2. ensure you're on the latest alembic

3. have you tried the latest master of alembic? there's a MySQL-related fix to unique indexes that is yet unreleased.

[sqlalchemy-bot]

Changes by Michael Bayer (@zzzeek):

• added labels: on hold

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

confirmed with postgresql

[sqlalchemy-bot]

Changes by Michael Bayer (@zzzeek):

• removed labels: on hold

[sqlalchemy-bot]

dan milon (@danmilon) wrote:

Yes, the target database is postgresql :)
Still want me to test with master?

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

no I have the issue but this index will need to be excluded entirely for now

[sqlalchemy-bot]

Changes by dan milon (@danmilon):

• edited description

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

• Postgresql "functional" indexes are necessarily skipped from the
  autogenerate process, as the SQLAlchemy backend currently does not
  support reflection of these structures. A warning is emitted
  both from the SQLAlchemy backend as well as from the Alembic
  backend for Postgresql when such an index is detected.
  fixes #282

→ 46761f9

[sqlalchemy-bot]

Changes by Michael Bayer (@zzzeek):

• changed status to closed