Question

我正在尝试创建一个包含2个coloumns的视图，一个PatrolID和一个表示巡逻长度的数值（以分钟为单位）。巡逻在TYPE coloumn中标记为已启动，变量为PATROL_STARTED和PATROL_FINISHED。这些时间的时间为OCCURRENCE DATE coloumn，带有时间戳（日期时间）。

我尝试过以下操作，但似乎不想工作：

CREATE VIEW RouteDurations AS
SELECT PatrolID,
       DATEDIFF(mi, MAX(CASE WHEN ACTION="PATROL_FINISH" THEN [Occurrence Date] END),
                MIN(CASE WHEN ACTION="PATROL_START" THEN [Occurrence Date] END)
               ) AS Duration 
FROM [Data Import] AS t 
GROUP BY PatrolID

我不能为我的生活找出原因。有人拿起任何东西吗？

Answer 1

SQL Server不对字符串使用双引号。试试这个：

SELECT PatrolID,
       DATEDIFF(minute,
                MIN(CASE WHEN ACTION = 'PATROL_STARTED' THEN [Occurrence Date] END),
                MAX(CASE WHEN ACTION = 'PATROL_FINISHED' THEN [Occurrence Date] END)
               ) AS Duration 
FROM [Data Import] AS t 
GROUP BY PatrolID;

此外，datediff()的参数首先是开始日期，然后是结束日期。

Answer 2

您可能想要自我加入。像这样：

select p1.patrolID,
datediff(mi, p1.[Occurrence Date], p2.[Occurrence Date]) minutes
from [Data Import] p1 join [Data Import] p2
on p1.patrolID = p2.patrolID
and p1.action = 'PATROL_START'
and p2.action = 'PATROL_FINISH'
where p1.patrolID = something

我需要使用DATEDIFF来获得路线巡逻的开始和结束之间的分钟差异

2 个答案: