Duplicate Column names

[UndefinedOffset]

Looks like there maybe an issue with duplicate column names, we should ensure we're targeting the right table. http://stackoverflow.com/questions/17226300/sortablegridfield-causing-sql-error/20985634#20985634

[UndefinedOffset]

This is a limitation to the core of the framework DataQuery::max() takes the field name escapes it and quotes it as if it is a column before running the query see https://github.com/silverstripe/silverstripe-framework/blob/3.1/model/DataQuery.php#L343. As for the use of where() this has been replaced with filter(), though it may still have the same issue it depends on how the core handles it, I don't immediately see anywhere where the column's table is being detected.