Merge "Parse (but don't record) COMMENT portion of MySQL table key"

3 files changed, 22 insertions, 0 deletions

diff --git a/doc/build/changelog/changelog_11.rst b/doc/build/changelog/changelog_11.rst
index 31df8720f..619eb00ab 100644
--- a/doc/build/changelog/changelog_11.rst
+++ b/doc/build/changelog/changelog_11.rst
@@ -146,6 +146,15 @@
         :class:`.Engine`, concealing the URL password.  Pull request courtesy
         Valery Yundin.
 
+    .. change:: 3867
+        :tags: bug, mysql
+        :tickets: 3867
+
+        The MySQL dialect now will not warn when a reflected column has a
+        "COMMENT" keyword on it, but note however the comment is not yet
+        reflected; this is on the roadmap for a future release.  Pull request
+        courtesy Lele Long.
+
     .. change:: pg_timestamp_zero_prec
         :tags: bug, postgresql
 
diff --git a/lib/sqlalchemy/dialects/mysql/reflection.py b/lib/sqlalchemy/dialects/mysql/reflection.py
index d020fb296..f5f09b80b 100644
--- a/lib/sqlalchemy/dialects/mysql/reflection.py
+++ b/lib/sqlalchemy/dialects/mysql/reflection.py
@@ -359,6 +359,7 @@ class MySQLTableDefinitionParser(object):
             r'(?: +USING +(?P<using_post>\S+))?'
             r'(?: +KEY_BLOCK_SIZE *[ =]? *(?P<keyblock>\S+))?'
             r'(?: +WITH PARSER +(?P<parser>\S+))?'
+            r'(?: +COMMENT +(?P<comment>(\x27\x27|\x27([^\x27])*?\x27)+))?'
             r',?$'
             % quotes
         )
diff --git a/test/dialect/mysql/test_reflection.py b/test/dialect/mysql/test_reflection.py
index ddf158167..2ccb299bc 100644
--- a/test/dialect/mysql/test_reflection.py
+++ b/test/dialect/mysql/test_reflection.py
@@ -552,6 +552,18 @@ class RawReflectionTest(fixtures.TestBase):
             '  PRIMARY KEY (`id`) USING BTREE KEY_BLOCK_SIZE  = 16')
         assert not regex.match(
             '  PRIMARY KEY (`id`) USING BTREE KEY_BLOCK_SIZE = = 16')
+        assert regex.match(
+            "  KEY (`id`) USING BTREE COMMENT 'comment'")
+        # `SHOW CREATE TABLE` returns COMMENT '''comment'
+        # after creating table with COMMENT '\'comment'
+        assert regex.match(
+            "  KEY (`id`) USING BTREE COMMENT '''comment'")
+        assert regex.match(
+            "  KEY (`id`) USING BTREE COMMENT 'comment'''")
+        assert regex.match(
+            "  KEY (`id`) USING BTREE COMMENT 'prefix''suffix'")
+        assert regex.match(
+            "  KEY (`id`) USING BTREE COMMENT 'prefix''text''suffix'")
 
     def test_fk_reflection(self):
         regex = self.parser._re_constraint