Inserting content of SQL query in XML using FOR XML PATH

Question

I wrote a stored procedure that returns nvarchar variable that contains some generated SQL query, and second procedure, that generates XML using FOR XML PATH. I want to modify my procedure that generates XML and add content of my generated query from first procedure into generated XML.

Part of my procedure that generates XML:

SELECT @SQLStr = 'SELECT';

    DECLARE @tmp varchar(100), @tmpkod varchar(max);
    DECLARE c CURSOR LOCAL READ_ONLY FOR
    SELECT tableName, tableCode FROM @TableNames 
    OPEN c
    FETCH NEXT FROM c INTO @tmp, @tmpkod;
    WHILE @@FETCH_STATUS = 0 
    BEGIN

    SELECT @i = @i - 1;
    SELECT @SQLStr = @SQLStr + '(SELECT TOP 10 * FROM ' + @tmp + ' FOR XML PATH(''row''), TYPE) AS ' + @tmp + ',
    '
    EXEC GenerujSelectazXML @tmp, @tmpcode output;

    SELECT @SQLStr = @SQLStr + '(SELECT ' + @tmpCode + ' FOR XML PATH (''row''), TYPE) AS ' + @tmp + '_TEST'
    SELECT @tmpcode

    IF (@i <> 0) SELECT @SQLStr = @SQLStr + ',
    '
    ELSE SELECT  @SQLStr = @SQLStr + '
    '
    FETCH NEXT FROM c INTO @tmp, @tmpkod;
    END
    CLOSE c; DEALLOCATE c;

    SELECT @SQLStr = @SQLStr + 'FOR XML PATH(''''), ROOT(''root'')';

    EXEC (@SQLStr) 

I cannot simply put content of a query into XML, because it contains some special characters like " < ", " > ", and they are introducing/ending xml tags. So i thought that putting query command into XML comment will solve my problem.

I tried this:

    SELECT @SQLStr = '<!--' + @tmpCode + '-->';

and it didn't help, I got error:

Msg 102, Level 15, State 1, Line 3
Incorrect syntax near '<'.
Msg 137, Level 15, State 1, Line 4
Must declare the scalar variable "@xml".
Msg 137, Level 15, State 2, Line 216
Must declare the scalar variable "@xml".
Msg 156, Level 15, State 1, Line 217
Incorrect syntax near t he keyword 'FOR'.
Msg 137, Level 15, State 1, Line 219
Must declare the scalar variable "@xml".
Msg 137, Level 15, State 2, Line 416
Must declare the scalar variable "@xml".
Msg 156, Level 15, State 1, Line 417
Incorrect syntax near the keyword 'FOR'.
Msg 137, Level 15, State 1, Line 419
Must declare the scalar variable "@xml".
Msg 137, Level 15, State 2, Line 540
Must declare the scalar variable "@xml".

I also tried this:

SELECT @SQLStr = '<![CDATA[' + @tmpCode + N']]>';

it didn't help, either.

Error message that I got:

Msg 102, Level 15, State 1, Line 3
Incorrect syntax near '<'.
Msg 103, Level 15, State 4, Line 3
The identifier that starts with CDATA[DECLARE @xml xml SELECT TOP 1 @xml = x FROM iksemel ORDER BY id INSERT INTO ARTYKUL_TEST(ID_ARTYKULU,ID_MAGAZYNU' is too long. Maximum length is 128.
Msg 105, Level 15, State 1, Line 541
Unclosed quotation mark after the character string ')'.

Please help

Answer 1

Could you provide an example of the xml you're trying to generate? Based on the code you posted, I'm assuming it looks something like this.

<root>
  <Instructors>
    <row>
      <InstructorName>Graff</InstructorName>
    </row>
  </Instructors>
 <Instructors_TEST>
   <row>0</row>
 </Instructors_TEST>
</root>

You'll need to modify your generated SQL to be more like this:

SELECT (
  SELECT * FROM Instructors FOR XML PATH('row'), TYPE
) AS Instructors,
(
  SELECT 0 FROM Instructors FOR XML PATH('row'), TYPE
) AS Instructors_TEST
FOR XML PATH(''), ROOT('root')

The problem is not with the value (query) you're trying to store in the xml. Do a SELECT on the @tmpCode, paste it into the editor, and check whether its a valid string. It's not.

In your code, you'd get this:

SELECT @tmpCode = '''SELECT value(''ID_ARTYKULU[1]'')'''
--'SELECT value('ID_ARTYKULU[1]')'

But you want to use this:

SELECT @tmpCode = '''SELECT value(''''ID_ARTYKULU[1]'''')'''
--'SELECT value(''ID_ARTYKULU[1]'')'

A ghetto fix would be to replace your @tmpCode section with this:

SELECT @tmpCode = N'''' + REPLACE('SELECT value(''ID_ARTYKULU[1]'')', N'''', N'''''') + N''''

Since you're using dynamic SQL, you need to be very careful when escaping quotes.