Add loose typed column support for get_column_key

CHANGES.rst

@@ -3,6 +3,14 @@ Changelog
 
 Here you can see the full list of changes between each SQLAlchemy-Utils release.
 
+
+0.27.11 (2014-12-06)
+^^^^^^^^^^^^^^^^^^^^
+
+- Added loose typed column checking support for get_column_key
+- Made get_column_key throw UnmappedColumnError to be consistent with SQLAlchemy
+
+
 0.27.10 (2014-12-03)
 ^^^^^^^^^^^^^^^^^^^^
 

sqlalchemy_utils/functions/orm.py

@@ -35,14 +35,21 @@ def get_column_key(model, column):
         get_column_key(User, User.__table__.c.name)  # 'name'
 
     .. versionadded: 0.26.5
+
+    .. versionchanged: 0.27.11
+        Throws UnmappedColumnError instead of ValueError when no property was
+        found for given column. This is consistent with how SQLAlchemy works.
     """
-    for key, c in sa.inspect(model).columns.items():
-        if c is column:
+    mapper = sa.inspect(model)
+    try:
+        return mapper.get_property_by_column(column).key
+    except sa.orm.exc.UnmappedColumnError:
+        for key, c in mapper.columns.items():
+            if c.name == column.name and c.table is column.table:
                 return key
-    raise ValueError(
-        "Class %s doesn't have a column '%s'",
-        model.__name__,
-        column
+    raise sa.orm.exc.UnmappedColumnError(
+        'No column %s is configured on mapper %s...' %
+        (column, mapper)
     )
 
 

tests/functions/test_get_column_key.py

@@ -1,3 +1,4 @@
+from copy import copy
 from pytest import raises
 
 import sqlalchemy as sa
@@ -15,7 +16,12 @@ class TestGetColumnKey(object):
             id = sa.Column(sa.Integer, primary_key=True)
             name = sa.Column('_name', sa.Unicode(255))
 
+        class Movie(Base):
+            __tablename__ = 'movie'
+            id = sa.Column(sa.Integer, primary_key=True)
+
         self.Building = Building
+        self.Movie = Movie
 
     def test_supports_aliases(self):
         assert (
@@ -29,6 +35,10 @@ class TestGetColumnKey(object):
             'name'
         )
 
+    def test_supports_vague_matching_of_column_objects(self):
+        column = copy(self.Building.__table__.c._name)
+        assert get_column_key(self.Building, column) == 'name'
+
     def test_throws_value_error_for_unknown_column(self):
-        with raises(ValueError):
-            get_column_key(self.Building, 'unknown')
+        with raises(sa.orm.exc.UnmappedColumnError):
+            get_column_key(self.Building, self.Movie.__table__.c.id)