Positional column numbers is not always correct for ORDER BY and GROUP BY
|Reported by:||Michael Manfre||Owned by:||nobody|
|Component:||Database layer (models, ORM)||Version:||master|
|Has patch:||no||Needs documentation:||no|
|Needs tests:||no||Patch needs improvement:||no|
"SELECT ... GROUP BY 1 ORDER BY 1" is very fragile and may not associate with the intended column if any columns are front loaded on to the select. Columns are front loaded by extra() and could be added by 3rd party database backends.
There are discussions of no longer front loading the extra() select columns. Assuming this change happens, the problem space would be reduced to just 3rd party backends, which would need some way to know that there are positional values in the query or would need an easier way of injecting columns in to the select without resorting to the simple front loading.