having is less annoying way of not doing needless/bug-prone repetition. if you select someCalculatedValue(someInput) as lol you can add having lol > 42 in mysql, whereas without (ie in pgsql) you’d need to do where someCalculatedValue(someInput) > 42, and make sure changes to that call stay in sync despite how far apart they are in a complex sql statement.
Postgres has the having clause. If it didn’t, that wouldn’t work, as you can’t use aggregates in a where. If you have to make do without having, for some reason, you can use a subquery, something like select * from (select someCalculatedValue(someInput) as lol) as stuff where lol > 42, which is very verbose, but doesn’t cause the sync problem.
Also, I don’t think they were saying the capability having gives is bad, but that a new query language should be designed such that you get that capability without it.
Well, if you lose the OOPism of those dots, we can talk.
Anyway, I’m really against the “having” tag. You need another keyword so that you can apply your filter after the group by?
That’s a good point, I didn’t even think about it, maybe a more functional style would make more sense?
Boy then are you going to hate
QUALIFYYes, I do. It’s a lot of effort and hidden functionality to try to paper over the fact that the statements do not compose.
having is less annoying way of not doing needless/bug-prone repetition. if you
select someCalculatedValue(someInput) as lolyou can addhaving lol > 42in mysql, whereas without (ie in pgsql) you’d need to dowhere someCalculatedValue(someInput) > 42, and make sure changes to that call stay in sync despite how far apart they are in a complex sql statement.Postgres has the
havingclause. If it didn’t, that wouldn’t work, as you can’t use aggregates in awhere. If you have to make do withouthaving, for some reason, you can use a subquery, something likeselect * from (select someCalculatedValue(someInput) as lol) as stuff where lol > 42, which is very verbose, but doesn’t cause the sync problem.Also, I don’t think they were saying the capability
havinggives is bad, but that a new query language should be designed such that you get that capability without it.