如何从sql server中的一个Record的多个值中仅获取指定的值记录

i have a table 'DEMO' like below, I need some specified result in my select query

我有一个表'DEMO'如下,我需要在我的选择查询中的一些指定结果

 PID   Is_Viewed
  1      False          
  1      False     
  1      False      
  1      False  
  2      True
  2      False

Now i need to select only those record which if having even a single value 'True' then result will be 1 else 0 in select statment. i have tried much but not getting the desired result... my query is

现在我只需要选择那些记录,如果甚至只有一个值'True',那么结果将是选择参数中的其他0。我已经尝试了很多,但没有得到理想的结果...我的查询是

/// select statement
    SELECT distinct PId,CASE WHEN EXISTS(Select Is_Viewed from DEMO where Is_viewed=1) then 1 else 0 end as Is_viewed FROM DEMO


    i WANT result like

    PId     Is_Viewed
    1        0
    2        1

3 个解决方案

#1

Maybe something like this:

也许是这样的:

SELECT
    PId,
    MAX(CASE WHEN Is_Viewed='True' THEN 1 ELSE 0 END) AS Is_Viewed
FROM
    DEMO
GROUP BY
    PId

Edit

Considering the data that you have supplied.

考虑您提供的数据。

DECLARE @tbl TABLE(PID INT,Is_Viewed VARCHAR(10))
INSERT INTO @tbl
VALUES
(1,'False'),          
(1,'False'),  
(1,'False'),      
(1,'False'),  
(2,'True'),
(2,'False')

With this query

有了这个查询

SELECT
    PId,
    MAX(CASE WHEN Is_Viewed='True' THEN 1 ELSE 0 END) AS Is_Viewed
FROM
    @tbl AS tbl
GROUP BY
    PId

The output is this:

输出是这样的:

PId     Is_Viewed
1       0
2       1

#2

I guess that Is_Viewed is defined as a bit type since SQL server doesn't have a BOOLEAN type. Then try this:

我猜Is_Viewed被定义为比特类型,因为SQL服务器没有BOOLEAN类型。然后尝试这个:

SELECT PID,
       MAX(CAST(Is_Viewed as INT)) as Is_Viewed 
FROM T
GROUP BY PID

SQLFiddle demo

#3

DECLARE @tbl TABLE(PID INT,Is_Viewed VARCHAR(10))
INSERT INTO @tbl
VALUES
(1,'False'),          
(1,'False'),  
(1,'False'),      
(1,'False'),  
(2,'True'),
(2,'False')



select distinct t.PID,
    CASE WHEN t.Is_Viewed = 'TRUE' 
        THEN 1 ELSE 0 END As PType from @tbl t
    INNER JOIN 
        (Select MIN(PID)As PID,Is_Viewed 
                FROM @tbl
GROUP BY  Is_Viewed)AS KK
ON KK.PID = t.PID
AND KK.Is_Viewed = t.Is_Viewed

#1