Possible Duplicates:
Implode type function in SQL Server 2000?
Concatenate row values T-SQL
I have a view which I'm querying that looks like this:
BuildingName PollNumber ------------ ---------- Foo Centre 12 Foo Centre 13 Foo Centre 14 Bar Hall 15 Bar Hall 16 Baz School 17
I need to write a query that groups BuildingNames together and displays a list of PollNumbers like this:
BuildingName PollNumbers ------------ ----------- Foo Centre 12, 13, 14 Bar Hall 15, 16 Baz School 17
How can I do this in T-SQL? I'd rather not resort to writing a stored procedure for this, since it seems like overkill, but I'm not exactly a database person. It seems like an aggregate function like SUM() or AVG() is what I need, but I don't know if T-SQL has one. I'm using SQL Server 2005.
for SQL Server 2017 and up use:
STRING_AGG()
set nocount on;
declare @YourTable table (RowID int, HeaderValue int, ChildValue varchar(5))
insert into @YourTable VALUES (1,1,'CCC')
insert into @YourTable VALUES (2,2,'B<&>B')
insert into @YourTable VALUES (3,2,'AAA')
insert into @YourTable VALUES (4,3,'<br>')
insert into @YourTable VALUES (5,3,'A & Z')
set nocount off
SELECT
t1.HeaderValue
,STUFF(
(SELECT
', ' + t2.ChildValue
FROM @YourTable t2
WHERE t1.HeaderValue=t2.HeaderValue
ORDER BY t2.ChildValue
FOR XML PATH(''), TYPE
).value('.','varchar(max)')
,1,2, ''
) AS ChildValues
FROM @YourTable t1
GROUP BY t1.HeaderValue
SELECT
HeaderValue, STRING_AGG(ChildValue,', ')
FROM @YourTable
GROUP BY HeaderValue
OUTPUT:
HeaderValue
----------- -------------
1 CCC
2 B<&>B, AAA
3 <br>, A & Z
(3 rows affected)
for SQL Server 2005 and up to 2016, you need to do something like this:
--Concatenation with FOR XML and eleminating control/encoded character expansion "& < >"
set nocount on;
declare @YourTable table (RowID int, HeaderValue int, ChildValue varchar(5))
insert into @YourTable VALUES (1,1,'CCC')
insert into @YourTable VALUES (2,2,'B<&>B')
insert into @YourTable VALUES (3,2,'AAA')
insert into @YourTable VALUES (4,3,'<br>')
insert into @YourTable VALUES (5,3,'A & Z')
set nocount off
SELECT
t1.HeaderValue
,STUFF(
(SELECT
', ' + t2.ChildValue
FROM @YourTable t2
WHERE t1.HeaderValue=t2.HeaderValue
ORDER BY t2.ChildValue
FOR XML PATH(''), TYPE
).value('.','varchar(max)')
,1,2, ''
) AS ChildValues
FROM @YourTable t1
GROUP BY t1.HeaderValue
OUTPUT:
HeaderValue ChildValues
----------- -------------------
1 CCC
2 AAA, B<&>B
3 <br>, A & Z
(3 row(s) affected)
Also, watch out, not all FOR XML PATH
concatenations will properly handle XML special characters like my above example will.