having is less annoying way of not doing needless/bug-prone repetition. if you selectsomeCalculatedValue(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 (selectsomeCalculatedValue(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.
having is less annoying way of not doing needless/bug-prone repetition. if you
select someCalculatedValue(someInput) as lol
you can addhaving lol > 42
in 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
having
clause. 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
having
gives is bad, but that a new query language should be designed such that you get that capability without it.