如何使用Union方法或左外连接？

Question

我无法通过scr_SecuristLog加入#Temp。 我该怎么做？

CREATE TABLE #Temp (VisitingCount int, [Time] int )
 DECLARE @DateNow DATETIME,@i int,@Time int
    set @DateNow='00:00'  
    set @i=1;  
    while(@i<48)  
        begin  
set @DateNow = DATEADD(minute, 30, @DateNow)
set @Time = (datepart(hour,@DateNow)*60+datepart(minute,@DateNow))/30 
insert into #Temp(VisitingCount,[Time]) values(0,@Time )
set @i=@i+1
                end
select VisitingCount, [Time]
from #Temp as t
left outer join (
    select count(page) as VisitingCount, 
    (datepart(hour,Date)*60+datepart(minute,Date))/30 as [Time]
    from scr_SecuristLog
    where Date between '2009-05-04' and '2009-05-05'
) as s
    on t.VisitingCount = s.VisitingCount
        and t.Time = s.Time

此代码给出错误：

---

消息8120，级别16，状态1，行1列'scr_SecuristLog.Date'在选择列表中无效，因为它不包含在聚合函数或GROUP BY子句中。
消息8120，级别16，状态1，行1列'scr_SecuristLog.Date'在选择列表中无效，因为它不包含在聚合函数或GROUP BY子句中。
消息209，级别16，状态1，行1不明确的列名称'VisitingCount'。
消息209，级别16，状态1，行1不明确的列名称“时间”。

Answer 1

由于您没有提到特定错误，我猜您的错误来自于您没有为选择值添加前缀的事实。

select t.VisitingCount, t.[Time]

---

编辑

您的第二个错误应该由此组解决。

select count(page) as VisitingCount, 
(datepart(hour,Date)*60+datepart(minute,Date))/30 as [Time]
from scr_SecuristLog
where Date between '2009-05-04' and '2009-05-05'
GROUP BY (datepart(hour,Date)*60+datepart(minute,Date))/30

Answer 2

我认为您需要在派生表scr_SecuristLog中添加GROUP BY，您需要按时间对其进行分组，因为您使用的是聚合函数计数。

Answer 3

CREATE TABLE #Temp (
  VisitingCount INT,
  [Time] INT)
DECLARE @DateNow DATETIME,
  @i INT,
  @Time INT
SET @DateNow = '00:00'

SET @i = 1 ;

WHILE(@i < 48)

  BEGIN

    SET @DateNow = DATEADD(minute, 30, @DateNow)
    SET @Time = (DATEPART(hour, @DateNow) * 60 + DATEPART(minute, @DateNow))
      / 30 
    INSERT  INTO #Temp (VisitingCount, [Time])
    VALUES  (0, @Time)
    SET @i = @i + 1
  END
SELECT  VisitingCount,
        [Time]
FROM    #Temp AS t
UNION
SELECT  COUNT(page) AS VisitingCount,
        (DATEPART(hour, Date) * 60 + DATEPART(minute, Date)) / 30 AS [Time]
FROM    scr_SecuristLog
WHERE   Date BETWEEN '2009-05-04' AND '2009-05-05'
GROUP BY Date


DROP TABLE #Temp 

Answer 4

好的，试试吧

CREATE TABLE #Temp (VisitingCount int, [Time] int )
DECLARE @DateNow DATETIME,@i int,@Time int
set @DateNow='00:00'  
set @i=1;  
while(@i<48)  
    begin  
        set @DateNow = DATEADD(minute, 30, @DateNow)
        set @Time = (datepart(hour,@DateNow)*60+datepart(minute,@DateNow))/30 
        insert into #Temp(VisitingCount,[Time]) values(0,@Time )
        set @i=@i+1
    end
    select t.VisitingCount, t.[Time]
    from #Temp as t
    left outer join (
         select count(page) as VisitingCount, 
       (datepart(hour,Date)*60+datepart(minute,Date))/30 as [Time]
       from scr_SecuristLog
       where Date between '2009-05-04' and '2009-05-05'
       GROUP BY scr_SecuristLog.Date
   ) as s
    on t.VisitingCount = s.VisitingCount
    and t.Time = s.Time

Answer 5

您的内部选择（您正在加入）不会正确聚合。 你有一个计数和一列。 这意味着您需要按SQL列进行分组才能正确理解它。

select t.VisitingCount, t.[Time]
from #Temp as t
left outer join (
    select count(page) as VisitingCount, 
    (datepart(hour,Date)*60+datepart(minute,Date))/30 as [Time]
    from scr_SecuristLog
    where Date between '2009-05-04' and '2009-05-05'
    GROUP BY [Date]
) as s
    on t.VisitingCount = s.VisitingCount
        and t.Time = s.Time

您可能实际需要的是按计算列进行分组，在这种情况下，您的分组应该是：

GROUP BY (datepart(hour,Date)*60+datepart(minute,Date))/30