.extra() should accept "having" parameter

[Carl Meyer]

Now that we can construct ORM queries with aggregates, it would be nice if the .extra() queryset method accepted a "having" parameter. It would work just like the current "where" parameter; would probably need an associated "having_params" argument, too.

[Alex Gaynor]

I am almost positive I saw malcolm reject a similar suggestion before, however since I can't find it I'm going to mark as DDN.

[django@…]

I would also like to see this feature. I am using a local implementation as a workaround to #11293, where HAVING clauses lose their connectors. This feature would also need to be taken into account for any fix to #11104.

[Carl Meyer]

@Alex I know that new QuerySet _methods_ that map directly to SQL implementation have often been rejected (with good reason, IMO), but extra() is in a different category: it's already tied directly to SQL terms and implementations. This proposal doesn't change the nature of extra(), just fleshes out its functionality.

[fetzig]

whats the use of being able use aggregates and not being able to set a having cause?

why is after a year still a "Design decision needed"?

[Aymeric Augustin]

Change UI/UX from NULL to False.

[Aymeric Augustin]

Change Easy pickings from NULL to False.

[anonymous]

3 years and this still isn't fixed?

So people on mysql can use extra to specify extra params, but the only way to do filtering on those is via the HAVING clause, as the WHERE clause isn't aware of those params.

So if comment #1 is correct, and this was rejected for some ridiculous reason, then it almost looks like explicitly targeting mysql users, as other db users can use the standard extra(where=...) to handle filtering, but mysql users are denied access to HAVING because of one asshole with a head full of bad decisions, who probably didn't even understand the ramifications of his actions.

So for mysql users, there is NO WAY TO FILTER USING THE PARAMS DEFINED IN EXTRA. Is this more or less correct? And no one has any intention of fixing it?

Isn't that precious!

[Alex Gaynor]

We've generally been in the direction of restricting (and hopefully) removing extra(), rather than expanding it. Therefore wontfixing this.