- Added new test coverage for so-called "down adaptions" of SQL types,

where a more specific type is adapted to a more generic one - this
use case is needed by some third party tools such as ``sqlacodegen``.
The specific cases that needed repair within this test suite were that
of :class:`.mysql.ENUM` being downcast into a :class:`.types.Enum`,
and that of SQLite date types being cast into generic date types.
The ``adapt()`` method needed to become more specific here to counteract
the removal of a "catch all" ``**kwargs`` collection on the base
:class:`.TypeEngine` class that was removed in 0.9. [ticket:2917]

1 files changed, 6 insertions, 5 deletions

diff --git a/lib/sqlalchemy/dialects/sqlite/base.py b/lib/sqlalchemy/dialects/sqlite/base.py
index 579a61046..d8aa58c2c 100644
--- a/lib/sqlalchemy/dialects/sqlite/base.py
+++ b/lib/sqlalchemy/dialects/sqlite/base.py
@@ -154,11 +154,12 @@ class _DateTimeMixin(object):
             self._storage_format = storage_format
 
     def adapt(self, cls, **kw):
-        if self._storage_format:
-            kw["storage_format"] = self._storage_format
-        if self._reg:
-            kw["regexp"] = self._reg
-        return util.constructor_copy(self, cls, **kw)
+        if issubclass(cls, _DateTimeMixin):
+            if self._storage_format:
+                kw["storage_format"] = self._storage_format
+            if self._reg:
+                kw["regexp"] = self._reg
+        return super(_DateTimeMixin, self).adapt(cls, **kw)
 
     def literal_processor(self, dialect):
         bp = self.bind_processor(dialect)