Working by group by for grouping data into string format

Question

I have a table that contains some data given below. It uses a tree like structure

i.e.

                Department

     SubD1,                       SubD2 .....

PreSubD1, PreSubD1...       PreSubD2, PreSubD2...       

---

pk_map_id            preferences          ImmediateParent      Department_Id
-------------------- -------------------- -------------------- --------------------
20                   14                   5                    1
21                   15                   5                    1
22                   16                   6                    1
23                   9                    4                    2
24                   4                    3                    2
25                   24                   20                   2
26                   25                   20                   2
27                   23                   13                   2

I want to group my records on behalf of department then immediate parent then preferences each separated by ','

i.e.

department  Immediate Parent  preferences
1             5,6                 14,15,16
2             4,3,20,13           9,4,24,25,23

and this table also

---

Immediate parent  preferences
5                     14,15
6                     16
4                     9
3                     4
20                    24,25
13                    13

In actual scenario all these are my ids which are to be replaced by their string fields.

I am using SQL server 2k5

Answer 1

You can use FOR XML PATH in a subquery to get the comma separated list of values. Then you GROUP BY your key field in order to get it for the right values.

For your first query

SELECT
    [Department_Id],
    STUFF(
    (
        SELECT
            ',' + CONVERT(varchar(10), [ImediateParent])
        FROM
            [YourTable] [YourTable2]
        WHERE
            [YourTable2].[Department_Id] = [YourTable].[Department_Id]
        FOR XML PATH('')
    ), 1, 1, ''),
    STUFF(
    (
        SELECT
            ',' + CONVERT(varchar(10), [Preferences])
        FROM
            [YourTable] [YourTable2]
        WHERE
            [YourTable2].[Department_Id] = [YourTable].[Department_Id]
        FOR XML PATH('')
    ), 1, 1, '')
FROM
    [YourTable]
GROUP BY
    [YourTable].[Department_Id]

and for your second query

SELECT
    [ImediateParent],
    STUFF(
    (
        SELECT
            ',' + CONVERT(varchar(10), [Preferences])
        FROM
            [YourTable] [YourTable2]
        WHERE
            [YourTable2].[ImediateParent] = [YourTable].[ImediateParent]
        FOR XML PATH('')
    ), 1, 1, '')
FROM
    [YourTable]
GROUP BY
    [YourTable].[ImediateParent]