java - When dealing with data relationships, what are the advantages and disadvantages of using database table foreign keys versus in-code maintenance?

Question

Recently I was designing a library table for an enterprise application project, and I encountered some data association problems. I was undecided whether it would be better to maintain within the code or make external associations. I am seeking the opinions of experts.

Answer 1

Let me tell you my personal opinion.
Normally, it is recommended to use database foreign keys. This has relatively complete constraints. Moreover, most applications (80%) of most companies have not yet reached the level of database segmentation. So why not just rely on the integrity of the database? ?

Not using foreign keys is usually too large, so the number should be more than a million. Need to be segmented. Only manually use the program maintenance. . .

Answer 2

The demand is stable - use foreign keys
The demand changes frequently - don’t use it