Request for Review: Ticket #10686

http://dev.rubyonrails.org/ticket/10686

I'd really appreciate it if a few people would test patch this out and
give feedback.

It changes the SQL generated by update_all so that passing :limit
or :order options will work with non-MySQL adapters. The SQL
currently generated creates SQL Exceptions for non-MySQL adapters.

Added tests pass for MySQL, PostgreSQL, and Sqlite3; I'm working on
tests to run (period) for other adapters, so testing those would be
most helpful.

Verification, comments, and +1s would be appreciated!

Thanks!
Brendan

The :limit and :order options are meant to apply to the UPDATE
statement directly -- simply don't use them with databases that don't
support it.

The issue you're seeing is that :limit and :order are being pulled
from the association scope -- this is a bug, IMO, and should be fixed
rather than adding roundabout support for a niche feature.

See http://dev.mysql.com/doc/refman/5.1/en/update.html for why you
sometimes want to use UPDATE ... ORDER BY with MySQL. It works around
duplicate key errors.

Best,
jeremy