True MySQL interview question (24) -- row column exchange

Exchange of ranks
Table name ：cook

The query results are as follows ：

SELECT  year ,
MAX(CASE WHEN  month =1 THEN  value  END) AS m1,
MAX(CASE WHEN  month =2 THEN  value  END) AS m2,
MAX(CASE WHEN  month =3 THEN  value  END) AS m3,
MAX(CASE WHEN  month =4 THEN  value  END) AS m4
FROM cook
GROUP BY  year