2 columns unique in mysql table

Question

Is it possible to make a 2 coulmns unique in mysql db? for example:

ID | columnA | columnB
 1 | Dan     | 1
 2 | Dan     | 2
 3 | Zak     | 1
 4 | Dan     | 1 (WHEN TRYING TO INSERT ROW 4 - NOT ALLOWED! DUPLICATE COULMNA + COLUMNB)

Answer 1

Try this:

ALTER TABLE tableA ADD UNIQUE INDEX idxColAB (columnA, columnB)