apply “ORDER BY” on a “UNION” (Mysql)

Question

Good Day. So, everythign is in the title :)

I am looking to merge the result of two requests and order the result together (as in not one after the other). => I was

Answer 1

SELECT a FROM t1 WHERE a=10 AND B=1
UNION
SELECT a FROM t2 WHERE a=11 AND B=2
ORDER BY 1 LIMIT 10;

if you need sort by more fields just add the number of the field, ORDER BY 1, 2, 3 LIMIT 10;