1.order by 排序

• 该表的所有数据

• asc 升序 -> 从小到大

select * from t1 order by id asc;

• desc 降序 -> 从大到小

select * from t1 order by id desc;

• 排序后如果遇到重复的数据可以再进行排序

select * from t1 order by age desc,id asc;