Implement comments for tables, columns

Added support for SQL comments on :class:`.Table` and :class:`.Column`
objects, via the new :paramref:`.Table.comment` and
:paramref:`.Column.comment` arguments.   The comments are included
as part of DDL on table creation, either inline or via an appropriate
ALTER statement, and are also reflected back within table reflection,
as well as via the :class:`.Inspector`.   Supported backends currently
include MySQL, Postgresql, and Oracle.

Co-authored-by: Mike Bayer <mike_mp@zzzcomputing.com>
Fixes: #1546
Change-Id: Ib90683850805a2b4ee198e420dc294f32f15d35d

1 files changed, 28 insertions, 1 deletions

diff --git a/test/sql/test_ddlemit.py b/test/sql/test_ddlemit.py
index e191beed3..25f9c595f 100644
--- a/test/sql/test_ddlemit.py
+++ b/test/sql/test_ddlemit.py
@@ -14,7 +14,9 @@ class EmitDDLTest(fixtures.TestBase):
         return Mock(dialect=Mock(
                     supports_sequences=True,
                     has_table=Mock(side_effect=has_item),
-                    has_sequence=Mock(side_effect=has_item)
+                    has_sequence=Mock(side_effect=has_item),
+                    supports_comments=True,
+                    inline_comments=False,
                     )
                     )
 
@@ -77,6 +79,26 @@ class EmitDDLTest(fixtures.TestBase):
 
         return m, t1, t2, s1, s2
 
+    def _table_comment_fixture(self):
+        m = MetaData()
+
+        c1 = Column('id', Integer, comment='c1')
+
+        t1 = Table(
+            't1', m, c1,
+            comment='t1'
+        )
+
+        return m, t1, c1
+
+    def test_comment(self):
+        m, t1, c1 = self._table_comment_fixture()
+
+        generator = self._mock_create_fixture(
+            False, [t1], item_exists=lambda t: t not in ("t1",))
+
+        self._assert_create_comment([t1, t1, c1], generator, m)
+
     def test_create_seq_checkfirst(self):
         m, t1, t2, s1, s2 = self._table_seq_fixture()
         generator = self._mock_create_fixture(
@@ -249,6 +271,11 @@ class EmitDDLTest(fixtures.TestBase):
             (schema.DropTable, schema.DropSequence, schema.DropConstraint),
             elements, generator, argument)
 
+    def _assert_create_comment(self, elements, generator, argument):
+        self._assert_ddl(
+            (schema.CreateTable, schema.SetTableComment, schema.SetColumnComment),
+            elements, generator, argument)
+
     def _assert_ddl(self, ddl_cls, elements, generator, argument):
         generator.traverse_single(argument)
         for call_ in generator.connection.execute.mock_calls: