Yeah, that was the q&d way I ended up implementing it - with 7 child tables. :) I just couldn't believe nobody had added an idiomatic way to do it in the language without jumping through hoops to get them. It's an immunization record - I wanted all the students that had shots for Measles 1, Measles 2, Mumps 1, Mumps 2, Rubella 1, Rubella 2, and NOT MMR1. Surprisingly enough, we actually have 12 active students who meet that criteria. :)
On Thu, Jun 22, 2023 at 3:41 PM Ted Roche <tedro...@gmail.com> wrote: > What's the relationship between parents and children (Isn't that the > universal question?) > > If parents can have many children and children can have many parents, > is there a M:M table to link them? > > If a child record has a single ParentFK, that's kinda sad. If you > want Parents that have *ALL FOUR* of those children, then a 4-times > join is the most likely simplest and easiest to read and maintain > later: > > SELECT * FROM Parent > join Child Child1 on ParentPK=Child1.ParentFK > join Child Child2 on ParentPK=Child2.ParentFK > join Child Child3 on ParentPK=Child3.ParentFK > join Child Child4 on ParentPK=Child4.ParentFK > Where Child1.field = 'a' and Child2.field='b' and Child3.field='c' and > Child4.field='d' > > While awkward to look at, it should be using only key fields and > optimized even by Oracle. > > On Thu, Jun 22, 2023 at 7:23 AM Garrett Fitzgerald > <sarekofvul...@gmail.com> wrote: > > > > Is there an idiomatic way to get parent records that have all of the > child > > records a, b, c, and d, short of joining the child table 4 times? Oracle > > 19, if it's relevant. > > > > > > --- StripMime Report -- processed MIME parts --- > > multipart/alternative > > text/plain (text body -- kept) > > text/html > > --- > > [excessive quoting removed by server] _______________________________________________ Post Messages to: ProFox@leafe.com Subscription Maintenance: https://mail.leafe.com/mailman/listinfo/profox OT-free version of this list: https://mail.leafe.com/mailman/listinfo/profoxtech Searchable Archive: https://leafe.com/archives This message: https://leafe.com/archives/byMID/CAGd8Mrd8ck7VQdr85D_s=kpw_cz7y7m+2cfj4i6msswxnn8...@mail.gmail.com ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.