SQL GROUP BY 和 ORDER BY 区别
摘要:
order by 是按表中某字段排列表中数据group by 是按某些字段分类。例如按 1.按年龄排序表中的记录select * from users order by age 2.按年龄分类表中数据(就是求各个年龄的人数)select age,count(*) as number1 from us 阅读全文
posted @ 2018-11-14 05:10 zhuyongzhe 阅读(1694) 评论(0) 推荐(0) 编辑