How to check the database for correctness?

Question

Database

Hello. I have a database with 5 tables. The first 4 tables have 2 fields (id, name), and the last one combines four name fields from previous tables + its own field.
How to know and check that this database is correct?

Answer 1

Excuse me, but what is the criterion for the correctness of the database?
If a relational DB, read about 5 normal forms and take 3NF as a rule.