Return Multiple Rows in One Cell - sql

Question

So I've looked around and seen the XML trick and the Variable trick, and neither really made enough sense to me to implement. What I have is a table with 4 Columns, The first is a unique identifier, the second is a relation to a different table, the third is varbinary(max), the last is a string. I want to combine columns three and four over column two. Is this possible?
Example of Data:
| FileId | UniqueI1 | BinaryData | FileName |
|---------+------------+--------------+----------|
| 1 | 1 | <byte> | asp.jpg |
| 2 | 1 | <byte> | asp1.jpg |
| 3 | 2 | <byte> | asp2.jpg |
| 4 | 2 | <byte> | asp3.jpg |
| 5 | 2 | <byte> | asp4.jpg |
Preferred Output:
| UniqueI1 | BinaryData | FileName |
|------------+------------------------------+------------------------------|
| 1 | <byte>, <byte> | asp.jpg, asp1.jpg |
| 2 | <byte>, <byte>, <byte> | asp2.jpg, asp3.jpg, asp4.jpg |
I appreciate any help you may be able to provide me.

Answer 1

Sounds like you're trying to group your data and aggregate the BinaryData and FileName columns by concatenating their values.
There are no built-in aggregates for concatenation in t-sql, but there are a couple of ways to reach the same results.
In my opinion, by far the easiest way is to write a custom aggregate in c# leveraging the CLR. But it can also be done using STUFF or XML. You should have a look at Does T-SQL have an aggregate function to concatenate strings?

Answer 2

Try this:
DECLARE #t TABLE
(
FileID INT ,
UniqueID INT ,
Data VARBINARY(100) ,
FileName VARCHAR(10)
)
INSERT INTO #t
VALUES ( 1, 1, 1, 'asp.jpg' ),
( 2, 1, 2, 'asp1.jpg' ),
( 3, 2, 3, 'asp2.jpg' ),
( 4, 2, 4, 'asp3.jpg' ),
( 5, 2, 5, 'asp4.jpg' )
SELECT UniqueID ,
MAX(ca.data) AS Data,
MAX(ca.name) AS Name
FROM #t t1
CROSS APPLY ( SELECT STUFF(
(SELECT ', ' + CONVERT(VARCHAR(MAX), t2.Data, 2)
FROM #t t2
WHERE t1.UniqueID = t2.UniqueID
ORDER BY FileID
FOR XML PATH('') ,
TYPE
).value('.', 'varchar(max)'), 1, 2, '') AS DATA ,
STUFF(
(SELECT ', ' + t2.FileName
FROM #t t2
WHERE t1.UniqueID = t2.UniqueID
ORDER BY FileID
FOR XML PATH('') ,
TYPE
).value('.', 'varchar(max)'), 1, 2, '') AS NAME
) ca
GROUP BY UniqueID
Output:
UniqueID Data Name
1 00000001, 00000002 asp.jpg, asp1.jpg
2 00000003, 00000004, 00000005 asp2.jpg, asp3.jpg, asp4.jpg
For pivoting:
WITH cte
AS ( SELECT * ,
ROW_NUMBER() OVER ( PARTITION BY UniqueID ORDER BY FileID ) AS rn
FROM #t
)
SELECT c.UniqueID ,
ca1.[1] AS Data1 ,
ca1.[2] AS Data2 ,
ca1.[3] AS Data3 ,
ca2.[1] AS File1 ,
ca2.[2] AS File2 ,
ca2.[3] AS File3
FROM cte c
CROSS APPLY ( SELECT *
FROM ( SELECT UniqueID ,
rn ,
Data
FROM cte ci
WHERE ci.UniqueID = c.UniqueID
) t PIVOT( MAX(Data) FOR rn IN ( [1], [2], [3] ) ) p
) ca1
CROSS APPLY ( SELECT *
FROM ( SELECT UniqueID ,
rn ,
FileName
FROM cte ci
WHERE ci.UniqueID = c.UniqueID
) t PIVOT( MAX(FileName) FOR rn IN ( [1], [2], [3] ) ) p
) ca2
GROUP BY c.UniqueID, ca1.[1], ca1.[2], ca1.[3], ca2.[1], ca2.[2], ca2.[3]
Output:
UniqueID Data1 Data2 Data3 File1 File2 File3
1 0x00000001 0x00000002 NULL asp.jpg asp1.jpg NULL
2 0x00000003 0x00000004 0x00000005 asp2.jpg asp3.jpg asp4.jpg
You can change this to dynamic query if you don't want to manually add additional files.