- document ForeignKeyConstraint columns / elements, fixes #2904

Change-Id: Ia50a3100d1bd88020c30224932b16aeadd7f4c75

1 files changed, 22 insertions, 0 deletions

diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py
index 08f23c4af..e6eabc461 100644
--- a/lib/sqlalchemy/sql/schema.py
+++ b/lib/sqlalchemy/sql/schema.py
@@ -2630,6 +2630,12 @@ class ColumnCollectionConstraint(ColumnCollectionMixin, Constraint):
         Constraint.__init__(self, **kw)
         ColumnCollectionMixin.__init__(self, *columns, _autoattach=_autoattach)
 
+    columns = None
+    """A :class:`.ColumnCollection` representing the set of columns
+    for this constraint.
+
+    """
+
     def _set_parent(self, table):
         Constraint._set_parent(self, table)
         ColumnCollectionMixin._set_parent(self, table)
@@ -2871,6 +2877,22 @@ class ForeignKeyConstraint(ColumnCollectionConstraint):
         self.columns.add(column)
         self.elements.append(fk)
 
+    columns = None
+    """A :class:`.ColumnCollection` representing the set of columns
+    for this constraint.
+
+    """
+
+    elements = None
+    """A sequence of :class:`.ForeignKey` objects.
+
+    Each :class:`.ForeignKey` represents a single referring column/referred
+    column pair.
+
+    This collection is intended to be read-only.
+
+    """
+
     @property
     def _elements(self):
         # legacy - provide a dictionary view of (column_key, fk)