I am new to database development and I'm sure my current problem is quite common. Unfortunately I couldn't find a solution yet - mainly because I'm not sure how to name it correctly ;) So if there is a solution available already or there is a better way to describe it, please tell me and I'll rename this post.
My problem is that I have a database with an M:N relationship and I'm looking for a way to check if a record already exists.
Books can have multiple places of publication as well as authors. To avoid duplicates, the database should be checked before a new book is added. If there is only one author and place of publication the query will return just one record:
But if there are for example two authors, 2 rows of the same book will be returned. To make it even more complicated, let's say there are two books with same title, year of publication and pagecount but different authors, this will be returned:
Thats where my problem starts: I want to check if the record with book_id "2" already exists (obviously without knowing the book_id) and if it exists what its book_id is. In this example the only way to achieve this is to check if both authors names (or IDs to make it a little bit shorter) are associated with one of the books having the destinct values in title, year and pagecount - and I don't have any idea how to do that (ideally in SQL).
So thank you in advance for your help :)