Hello!!
I want to only show items in a dropdown if those items are not present in another entity.For example:
My Screen is a detail screen for a movie. Assuming that a movie may have multiple genres I created a third Entity for a M-M relationship between Movies and MovieGenres.
I have a dropdown to assign the Genres to the Movie in it's detail screen and when I add a genre to the movie I want that genre to not appear in the dropdown because it is already associated to the movie.
Can someone help me to achieve that? Do I need to use advanced SQL queries with a subquery or am I overcomplicating it?
Thank you!
I believe the most direct and effective approach to select genres that are not associated with a specific movie is to use a SQL query within a Data Action that will return this genre list. The SQL query would be similar to this :
SELECT {Genres}.*
FROM {Genres}
WHERE {Genres}.[Id] NOT IN (
SELECT {MovieGenres}.[GenderId]
FROM {MovieGenres}
WHERE {MovieGenres}.[MovieId] = @MovieId
);
Thank you Adão, it worked perfectly! I was trying that option but there was something in my clause that was not written correctly and it was just giving me an error!
Kind regards,
Pedro Luís
Great 😄, I'm glad I was able to help. keep up the great work.