id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
1760	order_with_respect_to doesn't work with MySQL	Christopher Lenz <cmlenz@…>	nobody	"Inserting/updating an inline-edited object that has `order_with_respect_to` enabled results in the following traceback:

{{{
Traceback (most recent call last):
[snip]
File ""lib/django/django/db/models/base.py"" in save
File ""lib/django/django/db/backends/util.py"" in execute
File ""lib/django/django/db/backends/mysql/base.py"" in execute
File ""/usr/lib64/python2.4/site-packages/MySQLdb/cursors.py"" in execute
  137. self.errorhandler(self, exc, value)
File ""/usr/lib64/python2.4/site-packages/MySQLdb/connections.py"" in defaulterrorhandler
  33. raise errorclass, errorvalue

  OperationalError at /admin/products/productlocalization/4445/
  (1093, ""You can't specify target table 'products_download' for update in FROM clause"")
}}}

The SQL query causing this problem is:

{{{
#!sql
  INSERT INTO `products_download` (`product_id`,`title`,`file`,`type`,`_order`)
  VALUES (%s,%s,%s,%s,(SELECT COUNT(*) FROM `products_download` WHERE `product_id` = %s))
}}}

Apparently this is due to a limitation of MySQL regarding subqueries, [http://dev.mysql.com/doc/refman/5.0/en/update.html documented] on the page describing the `UPDATE` statement:

  ''Currently, you cannot update a table and select from the same table in a subquery.''"	defect	closed	Database layer (models, ORM)	dev	normal	fixed		farcepest@… simon@…	Ready for checkin	1	0	0	0	0	0