- try to document how to get columns from constraints.

unfortunately Sphinx refuses to work correctly for the columns
attribute so we just add a lame message to contains_column().

1 files changed, 8 insertions, 0 deletions

diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py
index 2120e303b..e022c5768 100644
--- a/lib/sqlalchemy/sql/schema.py
+++ b/lib/sqlalchemy/sql/schema.py
@@ -2373,6 +2373,7 @@ def _to_schema_column_or_string(element):
 
 
 class ColumnCollectionMixin(object):
+
     columns = None
     """A :class:`.ColumnCollection` of :class:`.Column` objects.
 
@@ -2455,6 +2456,13 @@ class ColumnCollectionConstraint(ColumnCollectionMixin, Constraint):
         return self._schema_item_copy(c)
 
     def contains_column(self, col):
+        """Return True if this constraint contains the given column.
+
+        Note that this object also contains an attribute ``.columns``
+        which is a :class:`.ColumnCollection` of :class:`.Column` objects.
+
+        """
+
         return self.columns.contains_column(col)
 
     def __iter__(self):