1:带条件查询，查询ID=2的数据
SELECT * FROM table WHERE ID = 2
2：查询前几条数据，如查询前2条数据
SELECT * FROM table LIMIT 2
3:降序/升序查询 desc降序 asc是升序
SELECT * FROM table order by number desc
4:更新
UPDATE musictable SET likeNumber = 110 where ID = 3
