can we improve select_from() specificity ?

[Mike Bayer]

from sqlalchemy import *
from sqlalchemy.orm import *
from sqlalchemy.ext.declarative import declarative_base

Base = declarative_base()

class Task(Base):
    __tablename__ = "task"

    taskid = Column(Integer, primary_key=True)
    name = Column(String)

baseTask = aliased(Task)

session = Session()

query = session.query(Task.name, baseTask.name)\
       .select_from(baseTask)\
       .join((Task, Task.taskid == baseTask.taskid))

print query



SELECT task_1.name AS task_1_name 
FROM task AS task_1 JOIN task ON task_1.taskid = task_1.taskid

[Mike Bayer]

patch:

diff -r fbd81de0ebdbc54b0df6ba08cc8309e1328888fa lib/sqlalchemy/orm/query.py
--- a/lib/sqlalchemy/orm/query.py   Tue Dec 11 16:31:41 2012 -0500
+++ b/lib/sqlalchemy/orm/query.py   Thu Dec 13 18:29:04 2012 -0500
@@ -163,17 +163,29 @@
                 self._polymorphic_adapters[m.local_table](m.local_table) = adapter

     def _set_select_from(self, *obj):
-
         fa = [       select_from_alias = None
         for from_obj in obj:
-            if isinstance(from_obj, expression.SelectBase):
-                from_obj = from_obj.alias()
-            fa.append(from_obj)
+            info = inspect(from_obj)
+
+            if hasattr(info, 'mapper') and \
+                (info.is_mapper or info.is_aliased_class):
+                self._select_from_entity = from_obj
+                fa.append(info.selectable)
+            elif not info.is_selectable:
+                raise sa_exc.ArgumentError(
+                        "argument is not a mapped class, mapper, "
+                        "aliased(), or FromClause instance.")
+            else:
+                if isinstance(from_obj, expression.SelectBase):
+                    from_obj = from_obj.alias()
+                select_from_alias = from_obj
+                fa.append(from_obj)

         self._from_obj = tuple(fa)

         if len(self._from_obj) == 1 and \
-            isinstance(self._from_obj[0](]
+), expression.Alias):
+            isinstance(select_from_alias, expression.Alias):
             equivs = self.__all_equivs()
             self._from_obj_alias = sql_util.ColumnAdapter(
                                                 self._from_obj[0](0), equivs)
@@ -2011,20 +2023,8 @@
         usage of :meth:`~.Query.select_from`.

         """
-        obj = []
-        for fo in from_obj:
-            info = inspect(fo)
-            if hasattr(info, 'mapper') and \
-                (info.is_mapper or info.is_aliased_class):
-                self._select_from_entity = fo
-                obj.append(info.selectable)
-            elif not info.is_selectable:
-                raise sa_exc.ArgumentError(
-                            "select_from() accepts FromClause objects only.")
-            else:
-                obj.append(fo)
-
-        self._set_select_from(*obj)
+
+        self._set_select_from(*from_obj)

     def __getitem__(self, item):
         if isinstance(item, slice):

[Mike Bayer]

ce3333a65c128d873a5c963a71d5c6961a42a3e8

[Mike Bayer]

Removing milestone: 0.8.0final (automated comment)