SQL SELECT: concatenated column with line breaks and heading per group - sql

Question

I have the following SQL result from a SELECT query:
ID | category| value | desc
1 | A | 10 | text1
2 | A | 11 | text11
3 | B | 20 | text20
4 | B | 21 | text21
5 | C | 30 | text30
This result is stored in a temporary table named #temptab. This temporary table is then used in another SELECT to build up a new colum via string concatenation (don't ask me about the detailed rationale behind this. This is code I took from a colleague). Via FOR XML PATH() the output of this column is a list of the results and is then used to send mails to customers.
The second SELECT looks as follows:
SELECT t1.column,
t2.column,
(SELECT t.category + ' | ' + t.value + ' | ' + t.desc + CHAR(9) + CHAR(13) + CHAR(10)
FROM #temptab t
WHERE t.ID = ttab.ID
FOR XML PATH(''),TYPE).value('.','NVARCHAR(MAX)') AS colname
FROM table1 t1
...
INNER JOIN #temptab ttab on ttab.ID = someOtherTable.ID
...
Without wanting to go into too much detail, the column colname becomes populated with several entries (due to multiple matches) and hence, a longer string is stored in this column (CHAR(9) + CHAR(13) + CHAR(10) is essentially a line break). The result/content of colname looks like this (it is used to send mails to customers):
A | 10 | text1
A | 11 | text11
B | 20 | text20
B | 21 | text21
C | 30 | text30
Now I would like to know, if there is a way to more nicely format this output string. The best case would be to group the same categories together and add a heading and empty line between different categories:
*A*
A | 10 | text1
A | 11 | text11
*B*
B | 20 | text20
B | 21 | text21
*C*
C | 30 | text30
My question is: How do I have to modify the above query (especially the string-concatenation-part) to achieve above formatting? I was thinking about using a GROUP BY statement, but this obviously does not yield the desired result.
Edit: I use Microsoft SQL Server 2008 R2 (SP2) - 10.50.4270.0 (X64)

Answer 1

Declare #YourTable table (ID int,category varchar(50),value int, [desc] varchar(50))
Insert Into #YourTable values
(1,'A',10,'text1'),
(2,'A',11,'text11'),
(3,'B',20,'text20'),
(4,'B',21,'text21'),
(5,'C',30,'text30')
Declare #String varchar(max) = ''
Select #String = #String + Case when RowNr=1 Then Replicate(char(13)+char(10),2) +'*'+Category+'*' Else '' end
+ char(13)+char(10) + category + ' | ' + cast(value as varchar(25)) + ' | ' + [desc]
From (
Select *
,RowNr=Row_Number() over (Partition By Category Order By Value)
From #YourTable
) A Order By Category, Value
Select Substring(#String,5,Len(#String))
Returns
*A*
A | 10 | text1
A | 11 | text11
*B*
B | 20 | text20
B | 21 | text21
*C*
C | 30 | text30

Answer 2

This should return what you want
Declare #YourTable table (ID int,category varchar(50),value int, [desc] varchar(50))
Insert Into #YourTable values
(1,'A',10,'text1'),
(2,'A',11,'text11'),
(3,'B',20,'text20'),
(4,'B',21,'text21'),
(5,'C',30,'text30');
WITH Categories AS
(
SELECT category
,'**' + category + '**' AS CatCaption
,ROW_NUMBER() OVER(ORDER BY category) AS CatRank
FROM #YourTable
GROUP BY category
)
,Grouped AS
(
SELECT c.CatRank
,0 AS ValRank
,c.CatCaption AS category
,-1 AS ID
,'' AS Value
,'' AS [desc]
FROM Categories AS c
UNION ALL
SELECT c.CatRank
,ROW_NUMBER() OVER(PARTITION BY t.category ORDER BY t.Value)
,t.category
,t.ID
,CAST(t.value AS VARCHAR(100))
,t.[desc]
FROM #YourTable AS t
INNER JOIN Categories AS c ON t.category=c.category
)
SELECT category,Value,[desc]
FROM Grouped
ORDER BY CatRank,ValRank
The result
category Value desc
**A**
A 10 text1
A 11 text11
**B**
B 20 text20
B 21 text21
**C**
C 30 text30