hard coded 'alembic_version' in _produce_net_changes of autogenerate.py

[sqlalchemy-bot]

Migrated issue, originally created by Christian Blume (@cblume)

Can we get rid of hard coded 'alembic_version' table name in _produce_net_changes() of autogenerate.py? This has implications for autogeneration of table migrations. Though, I am not sure how to fix this. Any ideas?

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

it would have to derive from the name given up in the Environment, shouldn't be hard. you can see the "# TODO" comment in _produce_net_changes() to that effect.

this unfortunately has no unit tests that affirm it either, would have to do that too:

#!diff

diff -r 03481917469dde2be467c352232cc38999c50507 alembic/autogenerate.py
--- a/alembic/autogenerate.py	Mon Oct 01 17:12:03 2012 -0400
+++ b/alembic/autogenerate.py	Fri Oct 05 10:41:33 2012 -0400
@@ -139,7 +139,9 @@
         'connection': connection,
         'dialect': connection.dialect,
         'context': context,
-        'opts': opts
+        'opts': opts,
+        'alembic_version': context._version.name,
+        'alembic_version_schema': context._version.schema
     }, connection
 
 def _indent(text):
@@ -156,7 +158,7 @@
                             include_symbol=None,
                             include_schemas=False):
     inspector = Inspector.from_engine(connection)
-    # TODO: not hardcode alembic_version here ?
+
     conn_table_names = set()
     if include_schemas:
         schemas = set(inspector.get_schema_names())
@@ -169,8 +171,11 @@
         schemas = [None]
 
     for s in schemas:
-        tables = set(inspector.get_table_names(schema=s)).\
-                difference(['alembic_version'])
+        tables = set(inspector.get_table_names(schema=s))
+
+        if s == autogen_context.get('alembic_version_schema'):
+            tables = tables.difference(
+                [autogen_context.get('alembic_version', 'alembic_version')])
         conn_table_names.update(zip([s] * len(tables), tables))
 
     metadata_table_names = OrderedSet([(table.schema, table.name)

[sqlalchemy-bot]

Changes by Michael Bayer (@zzzeek):

• added labels: autogenerate - detection

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

Issue #220 was marked as a duplicate of this issue.

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

• If the "alembic_version" table is present in the target metadata,
  autogenerate will skip this also. Pull request courtesy
  Dj Gilcrease. fixes need more checks for alembic_version in autogen #28
• The :paramref:.EnvironmentContext.configure.version_table
  and :paramref:.EnvironmentContext.configure.version_table_schema
  arguments are now honored during the autogenerate process, such that
  these names will be used as the "skip" names on both the database
  reflection and target metadata sides. fixes hard coded 'alembic_version' in _produce_net_changes of autogenerate.py #77

→ 9650ccf

[sqlalchemy-bot]

Changes by Michael Bayer (@zzzeek):

• changed status to closed