How to organize dependency of SQL links?

Question

Java

There are three tables that contain chemical elements of different types. According to the formulas, you need to calculate the total of which element is needed in what quantity. Let's take a value from table_1 with id_1 and multiply it by the value from table_2 with id_3, display it on the screen and then multiply it by the value from table_3 with id_8. Do I understand correctly that in this case I do not need to link tables by foreign keys, since there are no permanent links in this case? Just starting to learn SQL queries

Answer 1

Good afternoon!

Do I understand correctly that in this case I do not need to link tables by foreign keys, since there are no permanent links in this case?

I'll assume yes. Although for a more precise answer it would be nice to see the full problem.
In this case, you are looking for a row with a specific id and perform this or that operation. Moreover, as far as I understand, you have a chem. elements are scattered across 3 tables. If you cannot logically link these tables to each other, then most likely links through FK are not needed.
And this question is more about the SQL tag than the Java tag

Answer 2

If there are no specific relationships between elements, then foreign keys are not needed.