[SQL-CVS] r2989 - SQLObject/branches/0.8/docs

[<sub...@co...>]

Author: phd
Date: 2007-09-26 08:31:47 -0600 (Wed, 26 Sep 2007)
New Revision: 2989

Modified:
   SQLObject/branches/0.8/docs/Inheritance.txt
Log:
Updated Inheritance docs.


Modified: SQLObject/branches/0.8/docs/Inheritance.txt
===================================================================
--- SQLObject/branches/0.8/docs/Inheritance.txt	2007-09-26 14:31:36 UTC (rev 2988)
+++ SQLObject/branches/0.8/docs/Inheritance.txt	2007-09-26 14:31:47 UTC (rev 2989)
@@ -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
+  aliases).
+* 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
+  table.
 * 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