What is the best way to create relationships between tables?

Question

Software design

What is the best way to create relationships between tables. At the database level or at the framework level (Laravel, Yii2, etc.).
And does it affect the speed of receiving data?

Answer 1

"Communication" (Foreign keys) in the database ≠ communication in the code, hence the question is meaningless.

Answer 2

at the base level

Answer 3

It does not affect the speed of receiving data, tk. it is an integrity control tool. And it should be in the database, because. it is problematic to take it out of there, imagine how you will check for the uniqueness of the field of the added record in a table with millions of records.