- The include_properties and exclude_properties arguments

to mapper() now accept Column objects as members in
addition to strings.  This so that same-named Column
objects, such as those within a join(), can be
disambiguated.

- A warning is now emitted if a mapper is created against a
join or other single selectable that includes multiple
columns with the same name in its .c. collection,
and those columns aren't explictly named as part of
the same or separate attributes (or excluded).
In 0.7 this warning will be an exception.   Note that
this warning is not emitted when the combination occurs
as a result of inheritance, so that attributes
still allow being overridden naturally.
[ticket:1896].  In 0.7 this will be improved further.

- The primary_key argument to mapper() can now specify
a series of columns that are only a subset of
the calculated "primary key" columns of the mapped
selectable, without an error being raised.  This
helps for situations where a selectable's effective
primary key is simpler than the number of columns
in the selectable that are actually marked as
"primary_key", such as a join against two
tables on their primary key columns [ticket:1896].

1 files changed, 40 insertions, 18 deletions

diff --git a/lib/sqlalchemy/orm/mapper.py b/lib/sqlalchemy/orm/mapper.py
index c3e4b042e..1f2216cec 100644
--- a/lib/sqlalchemy/orm/mapper.py
+++ b/lib/sqlalchemy/orm/mapper.py
@@ -192,8 +192,14 @@ class Mapper(object):
         else:
             self.polymorphic_map = _polymorphic_map
 
-        self.include_properties = include_properties
-        self.exclude_properties = exclude_properties
+        if include_properties:
+            self.include_properties = util.to_set(include_properties)
+        else:
+            self.include_properties = None
+        if exclude_properties:
+            self.exclude_properties = util.to_set(exclude_properties)
+        else:
+            self.exclude_properties = None
 
         self.compiled = False
         
@@ -471,7 +477,7 @@ class Mapper(object):
             for col in self._columntoproperty
             if not hasattr(col, 'table') or 
             col.table not in self._cols_by_table)
-
+        
         # if explicit PK argument sent, add those columns to the 
         # primary key mappings
         if self.primary_key_argument:
@@ -479,13 +485,14 @@ class Mapper(object):
                 if k.table not in self._pks_by_table:
                     self._pks_by_table[k.table] = util.OrderedSet()
                 self._pks_by_table[k.table].add(k)
-
-        if self.mapped_table not in self._pks_by_table or \
-                len(self._pks_by_table[self.mapped_table]) == 0:
-            raise sa_exc.ArgumentError(
-                    "Mapper %s could not assemble any primary "
-                    "key columns for mapped table '%s'" % 
-                    (self, self.mapped_table.description))
+        
+        # otherwise, see that we got a full PK for the mapped table
+        elif self.mapped_table not in self._pks_by_table or \
+                    len(self._pks_by_table[self.mapped_table]) == 0:
+                raise sa_exc.ArgumentError(
+                        "Mapper %s could not assemble any primary "
+                        "key columns for mapped table '%s'" % 
+                        (self, self.mapped_table.description))
 
         if self.inherits and \
                 not self.concrete and \
@@ -537,7 +544,7 @@ class Mapper(object):
         if self.inherits:
             for key, prop in self.inherits._props.iteritems():
                 if key not in self._props and \
-                    not self._should_exclude(key, key, local=False):
+                    not self._should_exclude(key, key, local=False, column=None):
                     self._adapt_inherited_property(key, prop, False)
 
         # create properties for each column in the mapped table,
@@ -550,7 +557,8 @@ class Mapper(object):
 
             if self._should_exclude(
                             column.key, column_key,
-                             local=self.local_table.c.contains_column(column)
+                             local=self.local_table.c.contains_column(column),
+                             column=column
                             ):
                 continue
 
@@ -583,7 +591,7 @@ class Mapper(object):
                               % col.description)
             else:
                 instrument = True
-            if self._should_exclude(col.key, col.key, local=False):
+            if self._should_exclude(col.key, col.key, local=False, column=col):
                 raise sa_exc.InvalidRequestError(
                     "Cannot exclude or override the discriminator column %r" %
                     col.key)
@@ -625,8 +633,18 @@ class Mapper(object):
                     # existing ColumnProperty from an inheriting mapper.
                     # make a copy and append our column to it
                     prop = prop.copy()
+                else:
+                    util.warn(
+                            "Implicitly combining column %s with column "
+                            "%s under attribute '%s'.  This usage will be "
+                            "prohibited in 0.7.  Please configure one "
+                            "or more attributes for these same-named columns "
+                            "explicitly."
+                             % (prop.columns[-1], column, key))
+
                 prop.columns.append(column)
                 self._log("appending to existing ColumnProperty %s" % (key))
+                             
             elif prop is None or isinstance(prop, ConcreteInheritedProperty):
                 mapped_column = []
                 for c in columns:
@@ -1099,7 +1117,7 @@ class Mapper(object):
                     (MapperProperty, attributes.InstrumentedAttribute)) and \
                     hasattr(obj, '__get__')
 
-    def _should_exclude(self, name, assigned_name, local):
+    def _should_exclude(self, name, assigned_name, local, column):
         """determine whether a particular property should be implicitly
         present on the class.
 
@@ -1121,13 +1139,17 @@ class Mapper(object):
                             getattr(self.class_, assigned_name)):
                 return True
 
-        if (self.include_properties is not None and
-            name not in self.include_properties):
+        if self.include_properties is not None and \
+                name not in self.include_properties and \
+                (column is None or column not in self.include_properties):
             self._log("not including property %s" % (name))
             return True
 
-        if (self.exclude_properties is not None and
-            name in self.exclude_properties):
+        if self.exclude_properties is not None and \
+            (
+                name in self.exclude_properties or \
+                (column is not None and column in self.exclude_properties)
+            ):
             self._log("excluding property %s" % (name))
             return True