SQL Server: Convert single row to comma delimited (separated) format - sql

Question

As the title states, I need help in converting a single row of data E.g,
col1 col2 col3 <-- This are column names
value1 value2 value3
To something like
dataResult <-- this is the column name from running the procedure or call
value1,value2,value3
The requirements are that this call ( or rather procedure) needs to be able to accept the results of sql queries of any column length and is able to convert that row to a comma delimited string format. Been stuck at this for weeks any help would be greatly appreciated...
EDIT*
Assume the unique key is the first column. Also assume that only 1 row will be returned with each query. Multiple rows will never occur.
The idea is to convert that row to a comma separated string without having to select the column names manually (in a sense automatically convert the query results)

Answer 1

You might try it like this:
A declared table variable to mock-up as test table. Be aware of the NULL value in col2!
DECLARE #tbl TABLE(col1 VARCHAR(100),col2 VARCHAR(100),col3 VARCHAR(100));
INSERT INTO #tbl VALUES('test1',NULL,'test3');
--This is the query:
SELECT
STUFF(
(
SELECT ',' + elmt.value('.','nvarchar(max)')
FROM
(
SELECT
(
/*YOUR QUERY HERE*/
SELECT TOP 1 *
FROM #tbl
/*--------------------*/
FOR XML AUTO ,ELEMENTS XSINIL,TYPE
)
) AS A(t)
CROSS APPLY t.nodes('/*/*') AS B(elmt)
FOR XML PATH('')
),1,1,'')
FOR XML AUTO will return each row as XML with all the values within attributes. But this would omit NULL values. Your returned string would not inlcude the full count of values in this case. Stating ELEMENT XSINIL forces the engine to include NULL values into the XML. This CROSS APPLY t.nodes('/*/*') will return all the elements as derived table and the rest is re-conactenation.
See the double comma in the middle! This is the NULL value of col2
test1,,test3
ATTENTION: You must be aware, that the whole approach will break, if there is a comma part of a (string) column...
Hint
Better was a solution with XML or JSON. Comma separated values are outdated...

Answer 2

Applay the next Approach:-
Use For Xml to sperate comma,
Get Columns Names Via using INFORMATION_SCHEMA.COLUMNS.
According to your need, select TOP (1) for getting First
Row.
Demo:-
Create database MyTestDB
go
Use MyTestDB
go
Create table Table1 ( col1 varchar(10), col2 varchar(10),col3 varchar(10))
go
insert into Table1 values ('Value1','Value2','Value3')
insert into Table1 values ('Value11','Value12','Value13')
insert into Table1 values ('Value21','Value22','Value23')
go
Declare #Values nVarchar(400),
#TableName nvarchar (100),
#Query nvarchar(max)
Set #TableName = 'Table1'
Select #Values = Stuff(
(
Select '+'','' + ' + C.COLUMN_NAME
From INFORMATION_SCHEMA.COLUMNS As C
Where C.TABLE_SCHEMA = T.TABLE_SCHEMA
And C.TABLE_NAME = T.TABLE_NAME
Order By C.ORDINAL_POSITION
For Xml Path('')
), 1, 2, '')
From INFORMATION_SCHEMA.TABLES As T
where TABLE_NAME = #TableName
select #Values = right(#Values,len(#Values)-4)
select #Query = 'select top(1)' + #Values + ' from ' + #TableName
exec sp_executeSQL #Query
Result:-