From c85c89a11528d7f342fca9e04a56663521c774a2 Mon Sep 17 00:00:00 2001
From: Matthew Sills <matthew@eightminuteswest.com>
Date: Thu, 19 Dec 2019 10:03:12 -0500
Subject: [PATCH] render table name with schema

Fixed issue where COMMENT directives for PostgreSQL failed to correctly
include an explicit schema name, as well as correct quoting rules for
schema, table, and column names.  Pull request courtesy Matthew Sills.

Fixes: #637
Closes: #636
Pull-request: https://github.com/sqlalchemy/alembic/pull/636
Pull-request-sha: 703e27bab5b2d0907367dd03a4babb00ea5ee8aa

Change-Id: I319171b0596faf0bbea1b965e094d13acad14b6c
---
 alembic/ddl/postgresql.py     |  7 +++++--
 docs/build/unreleased/637.rst |  7 +++++++
 tests/test_postgresql.py      | 25 +++++++++++++++++++++----
 3 files changed, 33 insertions(+), 6 deletions(-)
 create mode 100644 docs/build/unreleased/637.rst

diff --git a/alembic/ddl/postgresql.py b/alembic/ddl/postgresql.py
index d5bcd177..9cb3c11e 100644
--- a/alembic/ddl/postgresql.py
+++ b/alembic/ddl/postgresql.py
@@ -17,6 +17,7 @@ from .base import alter_table
 from .base import AlterColumn
 from .base import ColumnComment
 from .base import compiles
+from .base import format_column_name
 from .base import format_table_name
 from .base import format_type
 from .base import RenameTable
@@ -280,8 +281,10 @@ def visit_column_comment(element, compiler, **kw):
     )
 
     return ddl.format(
-        table_name=element.table_name,
-        column_name=element.column_name,
+        table_name=format_table_name(
+            compiler, element.table_name, element.schema
+        ),
+        column_name=format_column_name(compiler, element.column_name),
         comment=comment,
     )
 
diff --git a/docs/build/unreleased/637.rst b/docs/build/unreleased/637.rst
new file mode 100644
index 00000000..a30afb7e
--- /dev/null
+++ b/docs/build/unreleased/637.rst
@@ -0,0 +1,7 @@
+.. change::
+    :tags: bug, postgresql
+    :tickets: 637
+
+    Fixed issue where COMMENT directives for PostgreSQL failed to correctly
+    include an explicit schema name, as well as correct quoting rules for
+    schema, table, and column names.  Pull request courtesy Matthew Sills.
diff --git a/tests/test_postgresql.py b/tests/test_postgresql.py
index 59c12001..fe2635bd 100644
--- a/tests/test_postgresql.py
+++ b/tests/test_postgresql.py
@@ -177,7 +177,7 @@ class PostgresqlOpTest(TestBase):
 
         context.assert_(
             "ALTER TABLE foo.t ALTER COLUMN c SET NOT NULL",
-            "COMMENT ON COLUMN t.c IS 'This is a column comment'",
+            "COMMENT ON COLUMN foo.t.c IS 'This is a column comment'",
         )
 
     @config.requirements.comments_api
@@ -191,7 +191,24 @@ class PostgresqlOpTest(TestBase):
             comment="This is a column comment",
         )
 
-        context.assert_("COMMENT ON COLUMN t.c IS 'This is a column comment'")
+        context.assert_(
+            "COMMENT ON COLUMN foo.t.c IS 'This is a column comment'"
+        )
+
+    @config.requirements.comments_api
+    def test_alter_column_add_comment_table_and_column_quoting(self):
+        context = op_fixture("postgresql")
+        op.alter_column(
+            "T",
+            "C",
+            existing_type=Boolean(),
+            schema="foo",
+            comment="This is a column comment",
+        )
+
+        context.assert_(
+            'COMMENT ON COLUMN foo."T"."C" IS \'This is a column comment\''
+        )
 
     @config.requirements.comments_api
     def test_alter_column_add_comment_quoting(self):
@@ -205,7 +222,7 @@ class PostgresqlOpTest(TestBase):
         )
 
         context.assert_(
-            "COMMENT ON COLUMN t.c IS 'This is a column ''comment'''"
+            "COMMENT ON COLUMN foo.t.c IS 'This is a column ''comment'''"
         )
 
     @config.requirements.comments_api
@@ -220,7 +237,7 @@ class PostgresqlOpTest(TestBase):
             existing_comment="This is a column comment",
         )
 
-        context.assert_("COMMENT ON COLUMN t.c IS NULL")
+        context.assert_("COMMENT ON COLUMN foo.t.c IS NULL")
 
     @config.requirements.comments_api
     def test_create_table_with_comment(self):
-- 
2.47.2