t-sql to create XML file using FOR XML Path, multilevel issues - sql-server

Question

I am creating an XML file to Upload to a 3rd party product. The file must begin with specific file and source information level and then it is followed with the specific data requirements/levels of EVENT and CREW members for those events.
I can create the initial level with the file/source information, and I have the data requirements exactly as they should be, but I cannot get them together in the same file between the "ROOT" level without the initial level repeating between each EVENT level or the an extra EVENT level as if they're nested. I've also managed to get a result with a ROW level that I did not define and the "tags" modified to < and &gt: instead of < >. I've done a good bit of research and tried using a union method, sub-selects, nesting methods as well many combinations of FOR XML PATH, AUTO, EXPLICIT, with and without elements. I've learned a lot, but I'm just not finding the right combination for the results I need.
The first example is the layout that is required. The second is one of the examples that is most common for my efforts, followed by the SQL that created it.
what it should be (FILEINFO level only once, only one EVENT level for each EVENT)
<ROOT>
<FILEINFO>
<SOURCE_ID>P</SOURCE_ID>
</FILEINFO>
<EVENT>
<DATE>2019-09-24T08:00:00</DATE>
<NO>1</NO>
<DEL_FLAG>false</DEL_FLAG>
<DATE_TIME_STAMP>2019-09-24T14:14:00</DATE_TIME_STAMP>
<CREW>
<LAST_NAME>DOE</LAST_NAME>
<DEL_FLAG>false</DEL_FLAG>
<DATE_TIME_STAMP>2019-09-24T14:14:00</DATE_TIME_STAMP>
</CREW>
</EVENT>
<EVENT>
<DATE>2019-09-16T12:30:00</DATE>
<NO>1</NO>
<DEL_FLAG>false</DEL_FLAG>
<DATE_TIME_STAMP>2019-09-16T18:20:00</DATE_TIME_STAMP>
<CREW>
<LAST_NAME>DOE</LAST_NAME>
<DEL_FLAG>false</DEL_FLAG>
<DATE_TIME_STAMP>2019-09-16T18:20:00</DATE_TIME_STAMP>
</CREW>
</EVENT>
</ROOT>
what i'm getting:
<ROOT>
<EVENT>
<FILEINFO>
<SOURCE_ID>P</SOURCE_ID>
</FILEINFO>
<EVENT>
<DATE>2019-09-16T08:00:00</DATE>
<NO>1</NO>
<DEL_FLAG>false</DEL_FLAG>
<DATE_TIME_STAMP>2019-09-16T15:12:00</DATE_TIME_STAMP>
<CREW>
<LAST_NAME>DOE</LAST_NAME>
<DEL_FLAG>false</DEL_FLAG>
<DATE_TIME_STAMP>2019-09-16T15:12:00</DATE_TIME_STAMP>
</CREW>
</EVENT>
</EVENT>
<EVENT>
<FILEINFO>
<SOURCE_ID>P</SOURCE_ID>
</FILEINFO>
<EVENT>
<DATE>2019-09-16T08:00:00</DATE>
<NO>1</NO>
<DEL_FLAG>false</DEL_FLAG>
<DATE_TIME_STAMP>2019-09-16T15:12:00</DATE_TIME_STAMP>
<CREW>
<LAST_NAME>DOE</LAST_NAME>
<DEL_FLAG>false</DEL_FLAG>
<DATE_TIME_STAMP>2019-09-16T15:12:00</DATE_TIME_STAMP>
</CREW>
</EVENT>
</EVENT>
... ...
most recent/simplest attempt that creates the above:
SELECT
(SELECT SOURCE_ID FROM (select 'P' as SOURCE_ID) FILEINFO ) AS 'FILEINFO/SOURCE_ID'
,[DATE] AS 'EVENT/DATE'
,[NO] AS 'EVENT/NO'
,[DEL_FLAG] AS 'EVENT/DEL_FLAG'
,[DATE_TIME_STAMP] AS 'EVENT/DATE_TIME_STAMP'
,'DOE' as 'EVENT/CREW/LAST_NAME'
,[DEL_FLAG2] as 'EVENT/CREW/DEL_FLAG'
,[DATE_TIME_STAMP3] as 'EVENT/CREW/DATE_TIME_STAMP'
FROM [dbo].XMLForFILEExport x
FOR XML path('EVENT'), elements, ROOT('ROOT') ;

Answer 1

This is easy, just use a sub-select and deal with this like it was a *normal column:
This easy SELECT will return the single <FILEINFO>
SELECT 'P' AS [FILEINFO/SOURCE_ID]
FOR XML PATH(''),ROOT('ROOT');
You see, that I used an empty PATH(), but I set the ROOT().
This is the result
<ROOT>
<FILEINFO>
<SOURCE_ID>P</SOURCE_ID>
</FILEINFO>
</ROOT>
Now we can start to add your events. First I need a mockup table to simulate your issue
DECLARE #mockupEventTable TABLE(ID INT IDENTITY,[NO] INT, [DATE] DATETIME, EventText VARCHAR(100));
INSERT INTO #mockupEventTable VALUES(1,'20190916','Event 1')
,(2,'20190917','Event 2');
--The query
SELECT 'P' AS [FILEINFO/SOURCE_ID]
,(
SELECT e.[DATE]
,e.[NO]
,e.EventText
,'Doe' AS [CREW/LASTNAME]
FROM #mockupEventTable e
FOR XML PATH('EVENT'),TYPE
) AS [*]
FOR XML PATH(''),ROOT('ROOT');
The result
<ROOT>
<FILEINFO>
<SOURCE_ID>P</SOURCE_ID>
</FILEINFO>
<EVENT>
<DATE>2019-09-16T00:00:00</DATE>
<NO>1</NO>
<EventText>Event 1</EventText>
<CREW>
<LASTNAME>Doe</LASTNAME>
</CREW>
</EVENT>
<EVENT>
<DATE>2019-09-17T00:00:00</DATE>
<NO>2</NO>
<EventText>Event 2</EventText>
<CREW>
<LASTNAME>Doe</LASTNAME>
</CREW>
</EVENT>
</ROOT>
You can see, that the sub-select will create the inner XML just as you need it. We have to specify ,TYPE in order to get this as typed XML. Try the same without. You will get the XML escaped, as if it was simple text...
And I specify AS [*] (the same was AS [node()]) to indicate, that the XML "column" has no own name, but should be inserted as is. This is not mandatory (try it without), but it makes things more readable...

Answer 2

That's because you specified the PATH "EVENT" already. Also you can remove the EVENT in the field name, e.g. 'EVENT/CREW/DATE_TIME_STAMP' can just be 'CREW/DATE_TIME_STAMP'
TO achieve what required, you can generate the xml with EVENT elementsand then insert the FILEINFO.
DECLARE #x xml;
SET #x=(SELECT
[DATE] AS 'DATE'
,[NO] AS 'NO'
,[DEL_FLAG] AS 'DEL_FLAG'
,[DATE_TIME_STAMP] AS 'DATE_TIME_STAMP'
,'DOE' as 'CREW/LAST_NAME'
,[DEL_FLAG2] as 'CREW/DEL_FLAG'
,[DATE_TIME_STAMP3] as 'CREW/DATE_TIME_STAMP'
FROM [dbo].XMLForFILEExport x
FOR XML path('EVENT'), elements, ROOT('ROOT'))
SET #x.modify('
insert <FILEINFO><SOURCE_ID>P</SOURCE_ID></FILEINFO>
as first
into (/ROOT)[1]');