IF condition1 THEN statements; ELSEIF condition2 THEN # OPTIONAL statements; ELSE # OPTIONAL statements; END IF;
select id, ( CASE WHEN qty_1 <= '23' THEN price WHEN '23' > qty_1 && qty_2 <= '23' THEN price_2 WHEN '23' > qty_2 && qty_3 <= '23' THEN price_3 WHEN '23' > qty_3 THEN price_4 ELSE 1 END) AS total from product;
IF condition THEN statements; ELSE else-statements; END IF;