Question

请解决此查询

select
    to_char(date_trunc('day',create_time),'DD Month YYYY') as date,
    to_char(min(create_time),'HH24:mi') as login_time where login_status = 1,
    to_char(max(create_time),'HH24:mi') as login_out where login_status = 0
from 
    users.access_log
where
    user_id = 1010
group by
    user_id, actionlink_id, date_trunc('day', create_time)

在“，”

处或附近收到错误

不知道怎么写to_char函数中的where条件。

Answer 1

您需要CASE expression，而不是WHERE：

select
    to_char(date_trunc('day',create_time),'DD Month YYYY') as date,
    case when login_status = 1 then to_char(min(create_time),'HH24:mi') end as login_time,
    case when login_status = 0 then to_char(max(create_time),'HH24:mi') end as login_out
from 
    users.access_log
where
    user_id = 1010
group by
    user_id, actionlink_id, date_trunc('day', create_time)

Answer 2

使用join将两个登录和注销行放在一起：

select
    to_char(date_trunc('day',create_time),'DD Month YYYY') as date,
    to_char(min(a.create_time),'HH24:mi') as login_time,
    to_char(max(b.create_time),'HH24:mi') as login_out
from users.access_log a
left join users.access_log b on b.user_id = a.user_id
   and b.login_status = 0
   and date_trunc('day', b.create_time) = date_trunc('day', a.create_time)
   and b.actionlink_id = a.actionlink_id
where a.user_id = 1010
and a.login_status = 1
group by a.user_id, a.actionlink_id, date_trunc('day', a.create_time)

错误：“，”附近的语法错误

2 个答案: