Check out example codes for "mysql select else if". It will help you in understanding the concepts better.

Code Example 1

SELECT SUM(IF(user.name LIKE '%bob%',1,0)) AS `total_bobs`,

Code Example 2

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;

Learn ReactJs, React Native from akashmittal.com