Hi folks,
I'm trying to put together a MySQL query to do something I don't know
how to do: get a list of materials that DON'T show up in a relational table.
For example, 3 tables:
1) lib.books : lots of bib data including book_id
2) lib.subjects: subj_code, selector, subject_name
3) relational: lists book_id & subj_code
I want to generate a list of books that are in lib.books that doesn't
have any subjects assigned to it.
I could do this with 2 queries, but it gets unwieldy: get a list of
distinct book_ids and AND/NOT them all together like:
SELECT * FROM books WHERE book_id != '4' and book_id != '7'...
That works on really small sets, but I don't want to go that route.
Is there a savvy way to structure this MySQL query. I don't even know
the language to use to look for this information.
Thanks for any help you can provide!
Ken
--
Ken Irwin
Reference Librarian
Thomas Library, Wittenberg University
|