I know this must be a common problem, but I'm not sure where to go. This occurs a few times inside a big nasty query, so here is the problem simplified. I just want one row per object, but the null on ColorOther gives me two rows.
I can think of a few things to try wrapping a query around this, but there must be something simpler... I'm off to read up on pivots.
Table structure
CREATE TABLE [dbo].[Colors](
[ColorId] [int] IDENTITY(1,1) NOT NULL,
[ColoredObjectId] [int] NOT NULL,
[ColorCode] [int] NOT NULL,
[ColorOther] [nvarchar](50) NULL,
CONSTRAINT [PK_Colors] PRIMARY KEY CLUSTERED
([ColorId] ASC)
Source data
ColorId ColoredObjectId ColorCode ColorOther
----------- --------------- ----------- ----------
1 1 1 NULL
2 1 2 NULL
3 1 4 purple
4 2 2 NULL
5 2 3 NULL
6 2 4 orange
7 3 1 NULL
8 3 3 NULL
9 3 4 green
Query
SELECT ColoredObjectId ,
ColorOther ,
MAX(CASE WHEN ColorCode = 1 THEN 1 ELSE 0 END) AS Yellow,
MAX(CASE WHEN ColorCode = 2 THEN 1 ELSE 0 END) AS Red ,
MAX(CASE WHEN ColorCode = 3 THEN 1 ELSE 0 END) AS Blue ,
MAX(CASE WHEN ColorCode = 4 THEN 1 ELSE 0 END) AS Other
FROM Colors
GROUP BY ColoredObjectId,
ColorOther
Output
ColoredObjectId ColorOther Yellow Red Blue Other
--------------- ---------- ----------- ----------- ----------- -----------
1 NULL 1 1 0 0
1 purple 0 0 0 1
2 NULL 0 1 1 0
2 orange 0 0 0 1
3 NULL 1 0 1 0
3 green 0 0 0 1
Desired output
ColoredObjectId ColorOther Yellow Red Blue Other
--------------- ---------- -------开发者_JAVA技巧---- ----------- ----------- -----------
1 purple 1 1 0 1
2 orange 0 1 1 1
3 green 1 0 1 1
I think this should return the desired output.
SELECT ColoredObjectId ,
MAX(ColorOther) AS ColorOther ,
MAX(CASE WHEN ColorCode = 1 THEN 1 ELSE 0 END) AS Yellow,
MAX(CASE WHEN ColorCode = 2 THEN 1 ELSE 0 END) AS Red ,
MAX(CASE WHEN ColorCode = 3 THEN 1 ELSE 0 END) AS Blue ,
MAX(CASE WHEN ColorCode = 4 THEN 1 ELSE 0 END) AS Other
FROM Colors
GROUP BY ColoredObjectId
Try this (I am not at a SQL box, so I can't test it, but it should be pretty close)
SELECT cc.ColoredObjectId ,
xx.ColorOther ,
MAX(CASE WHEN ColorCode = 1 THEN 1 ELSE 0 END) AS Yellow,
MAX(CASE WHEN ColorCode = 2 THEN 1 ELSE 0 END) AS Red ,
MAX(CASE WHEN ColorCode = 3 THEN 1 ELSE 0 END) AS Blue ,
MAX(CASE WHEN ColorCode = 4 THEN 1 ELSE 0 END) AS Other
FROM Colors cc
JOIN (select distinct ColorObjectID,ColorOther FROM colors
where colorOther is not null) xx on xx.colorObjectId=cc.colorobjectID
GROUP BY cc.ColoredObjectId,
xx.ColorOther
精彩评论