[cli] generate Related for m-to-n relation

[billy1624]

PR Info

• Closes Generate m-to-m relations with sea-orm-cli #1074
• Closes Generate m-to-m relations with sea-orm-cli #1066

Fixes

• The old logic of determining a m-to-n relation somehow require the relation to be a composite foreign key. However, this clearly not a must. So, I updated to logic to only require the intermediate table of a m-to-n relation to be with
  • Exactly 2 foreign keys
  • A primary key formed by exactly 2 columns
  • Number of primary key equals to number of column

[tyt2y3]

Interesting. I don't have much knowledge here, but I vaguely remember a discussion around 'how to infer a many-to-many relationship' was made a long while ago.

[tyt2y3]

Approve if it is only going to relax the requirement

[tyt2y3]

Feel free to merge

[kandrelczyk]

Hi @billy1624 ,
I've just came across this issue in my project. I have m-to-n relation that is not generated correctly by cli. Any idea when this will be merged?

[billy1624]

Hey @kandrelczyk, I'll merge this now and this will be release on our next patch version.