php - MySQL, Concatenate two columns

Question

There are two columns in a MySQL table: SUBJECT and YEAR.

I want to generate an alphanumeric unique number which holds the concatenated data from SUBJECT and YEAR.

How can I do this? Is it possible to use a simple operator like +?

Answer 1

You can use the CONCAT function like this:

SELECT CONCAT(`SUBJECT`, ' ', `YEAR`) FROM `table`

Update:

To get that result you can try this:

SET @rn := 0;

SELECT CONCAT(`SUBJECT`,'-',`YEAR`,'-',LPAD(@rn := @rn+1,3,'0'))
FROM `table`