Add explicit key query support to GAE DAL

[alfonsodg]

From mjwatson@gmail.com on January 19, 2011 22:46:10

Could we have some mechanism to support querying on an explicitly specified key via the GAE DAL. So we could use the DAL something like: ``` key = Key.from_path('A', 1, parent=Key.from_path('B', 2, parent=Key.from_path('C', 3, parent=Key.from_path('D', 4)))) model = db.A(db.A._gaeKey == key) <--- or something like this perhaps. ``` This is required as the key generated by GAE is composed of itself plus any parents it may have. ``` I.e. import google.appengine.ext.db as gae def txn() barry = Father(name='Barry') simon = Son(parent=barry, name='Simon') simon.put() barry.put() gae.run_in_tranaction(txn()) # assuming barry.id = 1, simon.id = 2 # to get Barry. barry = gae.get(Key.from_path('Father', 1)) # to get Simon (you need the parent key) simon = gae.get(Key.from_path('Simon', 2, parent=Key.from_path('Father', 1)) or simon = Son.get_by_id(2, parent=Key.from_path('Father', 1)) etc… etc… ``` _Original issue: http://code.google.com/p/web2py/issues/detail?id=161_

[alfonsodg]

From dly...@gmail.com on February 07, 2011 02:59:52

I have a private patch for the new DAL which will include the native GAE key in each row returned from the DAL. I do it by adding a last column with a special column name 'gaeRef' and then I patched the new DAL to store the native ref into that column. I made it the last column to maximize performance, so I don't have to search for it in the internal list.

[alfonsodg]

From mjwatson@gmail.com on March 03, 2011 02:11:37

http://groups.google.com/group/web2py/browse_thread/thread/7d31902bd092afcc/d21c0493c670edb6?lnk=gst&q=Keys#d21c0493c670edb6 Christian has provided a fix that has been tested by myself and works fine without altering the dal significantly.

Please refer to the last message on the above thread entitled Keys and GAE

[alfonsodg]

From massimo....@gmail.com on June 20, 2011 11:31:53

The patch linked was applied at the time.

Status: Fixed