autogenerate FK comparison (and uniques, indexes?) comparing on column.key, but reflection doesn't have this

[sqlalchemy-bot]

Migrated issue, originally created by Michael Bayer (@zzzeek)

given local metadata:

Table(
    't1', target_metadata,
    Column('t1_id', Integer, key='id', primary_key=True),
)

Table(
    't2', target_metadata,
    Column('t2_id', Integer, key='id', primary_key=True),
    Column('t2_t1id', Integer, key='t1id'),
    ForeignKeyConstraint(['t1id'], ['t1.id'])
)

the DDL for this is:

CREATE TABLE t1 (
	t1_id SERIAL NOT NULL, 
	t1_foo VARCHAR, 
	PRIMARY KEY (t1_id)
)


CREATE TABLE t2 (
	t2_id SERIAL NOT NULL, 
	t2_t1id INTEGER, 
	PRIMARY KEY (t2_id), 
	FOREIGN KEY(t2_t1id) REFERENCES t1 (t1_id)
)

autogenerate here fails because ddl.base._fk_spec is using column.key for the source columns:

diff --git a/alembic/ddl/base.py b/alembic/ddl/base.py
index d497253..6a5a5fc 100644
--- a/alembic/ddl/base.py
+++ b/alembic/ddl/base.py
@@ -172,10 +172,11 @@ def _columns_for_constraint(constraint):
 
 def _fk_spec(constraint):
     if util.sqla_100:
-        source_columns = constraint.column_keys
+        source_columns = [
+            constraint.parent.c[key].name for key in constraint.column_keys]
     else:
         source_columns = [
-            element.parent.key for element in constraint.elements]
+            element.parent.name for element in constraint.elements]
 
     source_table = constraint.parent.name
     source_schema = constraint.parent.schema

uq and ix seem to be using column.name and might be OK but tests should be added.

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

• Fixed bug in foreign key autogenerate where if the in-Python table
  used custom column keys (e.g. using the key='foo' kwarg to
  Column), the comparison of existing foreign keys to those specified
  in the metadata would fail, as the reflected table would not have
  these keys available which to match up. Foreign key comparison for
  autogenerate now ensures it's looking at the database-side names
  of the columns in all cases; this matches the same functionality
  within unique constraints and indexes.
  fixes autogenerate FK comparison (and uniques, indexes?) comparing on column.key, but reflection doesn't have this #260

→ d12da7c

[sqlalchemy-bot]

Changes by Michael Bayer (@zzzeek):

• changed status to closed