sql 查询问题求教

xuyl · 2016-03-23T04:53:15Z

有个数据表 userlog 如下：需要查询组装成如下表格：

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有个数据表 userlog 如下：

userlog

需要查询组装成如下表格：

result

userlog

查询

如下

SQL

5 replies • 2016-03-23 14:14:41 +08:00

halfcrazy

Mar 23, 2016

select user, count(*) as cnt, logintime from userlog order by cnt desc, logintime asc group by user

idblife

Mar 23, 2016

select user, count(*) ,min(logintime),max(logintime) from userlog

jhdxr

Mar 23, 2016

直接 select *，登录次数自己写代码统计即可（一个 string-int 的 map ， key 是用户， value 是次数）

klesh

Mar 23, 2016

目测一楼的 sql 不行
select user group by user 是可以，其它的字段必须是 aggregate function. select logintime 是不行的。另外 order 需要在 group 后面

1.分两次查询
SELECT user, count(*) AS cnt FROM userlog GROUP BY user ORDER BY cnt;
SELECT logintime FROM userlog WHERE user=? ORDER BY logintime;

2.利用 GROUP_CONCAT （ mysql 用得少，未实测，不保证书写正确）
SELECT user, count(*) AS cnt, GROUP_CONCAT(logintime SEPARATOR '\n' ORDER BY logintime) AS logintimes FROM userlog GROUP BY user ORDER BY cnt;

xuyl

Mar 23, 2016

@klesh 感谢，第二种类方法可用。