Date: 2007-09-26 08:32:11 -0600 (Wed, 26 Sep 2007)
New Revision: 2991
Updated Inheritance docs.
--- SQLObject/docs/Inheritance.txt 2007-09-26 14:31:58 UTC (rev 2990)
+++ SQLObject/docs/Inheritance.txt 2007-09-26 14:32:11 UTC (rev 2991)
@@ -282,7 +282,7 @@
Limitations and notes
-* Only simple inheritance will work. It is not possible to inherit
+* Only single inheritance will work. It is not possible to inherit
from multiple SQLObject classes.
* It is possible to inherit from an inherited class and this will
work well. In the above example, you can have a Chief class that
@@ -297,6 +297,18 @@
set lazyUpdate to True. If you need this, you have to patch SQLObject
and override many methods - _SO_setValue(), sync(), syncUpdate() at
least. Patches will be gladly accepted.
+* You'd better restrain yourself to simple use cases. The inheritance
+ implementation is easiliy choked on more complex cases.
+* A join between tables inherited from the same parent produces incorrect
+ result due to joins to the same parent table (they must use different
+* Inheritance works in two stages - first it draws the IDs from the parent
+ table and then it drwas the rows from the children tables. The first
+ stage could fail if you try to do complex things. For example,
+ Children.select(orderBy=Children.q.column, distinct=True)
+ could fail because at the first stage inheritance generates a SELECT
+ query for the parent table with ORDER BY the column from the children
* I made it because I needed to be able to have automatic
inheritance with linked tables.
* This version works for me; it may not work for you. I tried to do