Foreign key referencing

Question

Please a table has a foreign key but I need to use a different column in that table
For calculation in another table as a column its own please how do I go about it
Hope the question is understood

Answer 1

No, the foreign key column from the second table does not have to be used in the calculation. Here is a sample of what I think your query might look like:

SELECT (tbl1.col3*tbl2.col3) AS NewCol FROM tbl1 LEFT JOIN tbl2 ON tbl2.col2 = tbl1.col4;

Answer 2

Before I answer, let me reflect what I understand: you have two tables joined on a foreign key. You wish to use a field from the first table and a field from the second table to perform a calculation, and assign a new column name to the result. Is this accurate?

Answer 3

First I need to reference a column in another table but the column I need to reference is not a primary key and I am required to use that column for calculation in the referenced table.
Please do you understand the question now?

Answer 4

Thanks