sql - Constraining number of rows to a range -


if have 2 tables, let's doors , house.

the tables connected through foreign key (doors house). constraints 1 house has 2 - 10 doors.

what best way enforce on data level?

create table houses (id int primary key) create table doors (     id int primary key,     house_id int references houses(id)     )  create trigger doorscondition on doors  instead of insert     declare @max int, @min int     select @max = max(i), @min = min(i) (         select count(1) (             select house_id doors house_id = (select house_id inserted)             union             select house_id inserted) subquery         group house_id) subquery2       if (@max <= 10 , @min >= 2)         insert doors select * inserted     else         print 'the insert violates business constraint'

and corresponding trigger delete. can merge them one, i'm not sure it's worth it, things considered, in simple scenario.


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