From bd6ba3ac8274381e578c8e6c8018a7878fe94208 Mon Sep 17 00:00:00 2001
From: Lele Long <schemacs@gmail.com>
Date: Sat, 3 Dec 2016 13:10:07 -0500
Subject: [PATCH] Parse (but don't record) COMMENT portion of MySQL table key

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.

Fixes: #3867
Pull-request: https://github.com/zzzeek/sqlalchemy/pull/324
Change-Id: I869e29aba6766d0eda1e59af09a3e8e3748a3942
---
 doc/build/changelog/changelog_11.rst        |  9 +++++++++
 lib/sqlalchemy/dialects/mysql/reflection.py |  1 +
 test/dialect/mysql/test_reflection.py       | 12 ++++++++++++
 3 files changed, 22 insertions(+)

diff --git a/doc/build/changelog/changelog_11.rst b/doc/build/changelog/changelog_11.rst
index ead2925706..4c3cc949eb 100644
--- a/doc/build/changelog/changelog_11.rst
+++ b/doc/build/changelog/changelog_11.rst
@@ -139,6 +139,15 @@
         :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 d020fb2969..f5f09b80b3 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 ddf1581678..2ccb299bc5 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
-- 
2.47.3