MySQL junction table not updating after creating keys

Question

I first created 2 tables. Later I realized I needed to add a M:M relationship between the two, so I created a junction table and created the necessary relationships between the tables. The problem I'm running into is that after creating the junction table, it isn't automatically being populated with the data from the other 2 tables. Should this data be automatically pulled from the other tables, or am I missing something?

Answer 1

Unless you're explicitly INSERTing into the junction table, it's not going to go in there.

Of course, you could potentially use triggers for what you want to achieve.