SQL＆gt;为单个结果选择多行

Question

我有上表，我需要做的是，例如根据此图片，返回一行会显示：

Ticket ID |       Created       |       Assigned      | Time Difference  
    2     | 2015-05-31 09:18:44 | 2015-06-03 10:05:00 | $MATH_RESULT

此图片仅显示了一个示例，但我希望让它返回同时分配了＆＃39;＆＃39;时间和创造的＆＃39;时间。

我不是DBA，这有点超出了我的有限知识。有人可以帮我解决这个问题吗？

Answer 1

您可以使用join查找状态为“已创建”的行的“已分配”行：

select  c.ticket_id
,       c.timestamp
,       a.timestamp
,       datediff(a.timestamp, c.timestamp)
from    ticket c
join    ticket a
on      c.ticket_id = a.ticket_id
where   c.state = 'created'
        and a.state = 'assigned'

Answer 2

http://sqlfiddle.com/#!9/cf498/3

SELECT t.ticket_id,t.timestamp as created, t1.timestamp as assigned, (t1.timestamp - t.timestamp) as delay
FROM table1 t
LEFT JOIN table1 t1
ON t.ticket_id = t1.ticket_id
  AND t1.state = 'assigned'
WHERE t.ticket_id = 2
   and t.state = 'created'

或者如果您需要所有门票列表

SELECT t.ticket_id,t.timestamp as created, t1.timestamp as assigned, (t1.timestamp - t.timestamp) as delay
FROM table1 t
LEFT JOIN table1 t1
ON t.ticket_id = t1.ticket_id
  AND t1.state = 'assigned'
WHERE t.state = 'created'