SQL variable concatenation with xml - sql

Question

have the following table coming from this query:
SELECT
[Document],
[Description],
[Value],
FROM [DocDetails]
Document Description Value Line No_
120 First Row 100 1
120 Second Row 0 2
120 Third row 0 3
120 Fourth row 0 4
120 fifth row 0 5
120 sixth row 203 6
120 seventh row 256 7
120 eighth row 259 8
120 ninth row 0 9
120 tenth row 0 10
120 eleventh row 0 11
I need to concatenate the description according to the value. I would need such result:
Document Description Value
120 First Row;second row;Third row;Fourth row;fifth row 100
120 sixth row 203
120 seventh row 256
120 eighth row;ninth row;tenth row;eleventh row 259
I tried the following:
SELECT
[Document],
All_Descriptions = STUFF(
(SELECT ';' + Description AS [text()]
FROM [DocDetails] D1
WHERE D1.[Document] = D2.[Document]
FOR XML PATH('')),1,1,'')
FROM [DocDetails] D2
GROUP BY D2.[Document]
As I don't have a variable that specifies the order I am not able to concatenate properly ( the code above concatenates everything but that's not what I want). Also if I group by value I am not getting the desired result.
How can I tell SQL to basically "concatenate the row with an amount with all the following having value 0"
Thanks for your help!

Answer 1

This is another solution that works with SQL 2008 too.
DECLARE #DocDetails TABLE( [Document] int, [Description] varchar(20), [Value] int, [Line_No] int )
INSERT INTO #DocDetails VALUES
(120,'First Row',100,1),
(120,'Second Row',0,2),
(120,'Third row',0,3),
(120,'Fourth row',0,4),
(120,'fifth row',0,5),
(120,'sixth row',203,6),
(120,'seventh row',256,7),
(120,'eighth row',259,8),
(120,'ninth row',0,9),
(120,'tenth row',0,10),
(120,'eleventh row',0,11),
(121,'eleventh row',0,11)
;WITH
LinesWithValue AS (
SELECT *, ROW_NUMBER() OVER(PARTITION BY [Document] ORDER BY Line_No ) RN
FROM #DocDetails
WHERE Value > 0
)
,LinesWithNext AS (
SELECT L.*, L1.Line_No Next_Line_No
FROM LinesWithValue L
LEFT JOIN LinesWithValue L1 ON L.RN + 1 = L1.RN AND L.[Document] = L1.[Document]
)
,NewTable AS (SELECT
B.Document,
B.Description,
CASE B.Value WHEN 0 THEN A.Value ELSE B.Value END Value,
B.Line_No
FROM LinesWithNext A
FULL JOIN #DocDetails B ON A.[Document] = B.[Document] AND ( ( B.Line_No >= A.Line_No ) AND ( A.Next_Line_No IS NULL OR B.Line_No < A.Next_Line_No ) )
)
SELECT
[Document],
[Value],
All_Descriptions = STUFF(
(SELECT ';' + Description AS [text()]
FROM NewTable D1
WHERE D1.[Document] = D2.[Document] AND D1.[Value] = D2.[Value]
FOR XML PATH('')) , 1, 1, '')
FROM NewTable D2
GROUP BY D2.[Document], [Value]

Answer 2

Here's a way....
declare #table table(Document int,[Description] varchar(64), [Value] int, Line_No int)
insert into #table
values
(120,'First Row',100,1),
(120,'Second Row',0,2),
(120,'Third row',0,3),
(120,'Fourth row',0,4),
(120,'fifth row',0,5),
(120,'sixth row',203,6),
(120,'seventh row',256,7),
(120,'eighth row',259,8),
(120,'ninth row',0,9),
(120,'tenth row',0,10),
(120,'eleventh row',0,11)
--Find the end / anchor line which to stop the concatenation later
;with cte as(
select
t.Document
,t.[Value]
,t.Description
,t.Line_No
,Parent_Line = isnull(min(t2.Line_No) - 1, (select max(Line_No) from #table))
from
#table t
full join
#table t2 on t2.Document = t.Document
and t2.Line_No > t.Line_No
and t2.Value <> 0
where
t.Document is not null
group by
t.Document
,t.[Value]
,t.Line_No
,t.Description),
--Do the concatenation of the Description
cte2 as (
select
Document
,value
,All_Descriptions = STUFF((
SELECT ',' + t2.Description
FROM cte t2
WHERE t.Parent_Line = t2.Parent_Line
FOR XML PATH(''), TYPE).value('.', 'NVARCHAR(MAX)'), 1, 1, '')
,Parent_Line
from
cte t)
--Get max [Value] for uniqueness
select
Document
,All_Descriptions
,[Value] = max([Value])
from
cte2
group by
Document
,All_Descriptions
order by
max([Value])