asked on

Equivalent MySQL group_concat in SQL Server

Hi,
My table looks like this:
Field1 Field2
1 A
1 B
1 C
2 A
2 B
With this mysql command select field1, group_concat(field2) as field2 from t1 Group by field1, I could achieve this:
Field1 Field2
1 A,B,C
2 A,B
How can I achieve this SQL Server 2008 R2
Regards

Simon

It can be done in MSSQL with a little more effort, using a recursive CTE (common table expression). The code below was originally written by Quassnoi and posted on his ExplainExtended.com blog

WITH
        qs(Field1,Field2, rn, cnt) AS
        (
        SELECT  Field1,Field2,
                ROW_NUMBER() OVER (PARTITION BY Field1 ORDER BY Field2),
                COUNT(*) OVER (PARTITION BY Field1)
        FROM    Table1
        ),
        t (Field1,Field2, gc, rn, cnt) AS
        (
        SELECT  Field1,Field2,
                CAST(Field2 AS NVARCHAR(MAX)), rn, cnt
        FROM    qs
        WHERE   rn = 1
        UNION ALL
        SELECT  qs.Field1, qs.Field2,
                CAST(t.gc + ', ' + qs.Field2 AS NVARCHAR(MAX)),
                qs.rn, qs.cnt
        FROM    t
        JOIN    qs
        ON      qs.Field1 = t.Field1
                AND qs.rn = t.rn + 1
        )
SELECT  Field1, gc as Field2
FROM    t
WHERE   rn = cnt
order by Field1
OPTION (MAXRECURSION 0)

Open in new window

See it working here on SQL Fiddle

ASKER CERTIFIED SOLUTION

PortletPaul

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial