Merge row values into a CSV (a.k.a GROUP_CONCAT for SQL Server)
I have a table like:
EntityID AttributeID OptionText
5016 20 Paintings
5044 18 Female
5060 48 M
5060 48 F
5060 49 Apple
5060 49 Banana
5060 49 Cat
I want to create a view that will show:
5016 20 Paintings
5044 18 Female
5060 48 M,F
5060 49 Apple, Banana, Cat
Means The attributes values on every entity should be displayed separated by a comma.
The number of options can be varied.
Any help is appreciated!
For each pair of EntityID, AttributeID
use the XML path trick to generate the CSV
SELECT
M.EntityID, M.AttributeID,
SUBSTRING(CAST(foo.bar AS varchar(8000)), 2, 7999) AS Options
FROM
(
SELECT DISTINCT EntityID, AttributeID
FROM MyTable
) M
CROSS APPLY
(
SELECT
',' + OptionText
FROM
MyTable M2
WHERE
M.EntityID = M2.EntityID AND M.AttributeID= M2.AttributeID
FOR XML PATH ('')
) foo(bar)
Try the code below (I've included all test SQL so you don't have to practice on live data). You can view a working example here: https://data.stackexchange.com/stackoverflow/q/115141/
--Set up test table
CREATE TABLE #Table1 (EntityID INT, AttributeID INT, OptionText VARCHAR(50))
INSERT INTO #Table1
SELECT 5030, 48, 'M'
INSERT INTO #Table1
SELECT 5030, 48, 'F'
--Begin actual working SQL
SELECT T1.EntityID,
T1.AttributeID,
STUFF(( SELECT ', ' + T2.OptionText
FROM #Table1 T2
WHERE T2.AttributeID = T1.AttributeID
AND T2.EntityID = T1.EntityID
FOR XML PATH('')
), 1, 2, '') [Attributes]
FROM #Table1 T1
GROUP BY T1.EntityID, T1.AttributeID
DROP TABLE #Table1
I have done some tests with 3 different methods:
http://blog.feronovak.com/2011/10/multiple-values-in-one-column-aka.html
Hope it helps.