April 24, 2014 at 12:04 am
Comments posted to this topic are about the item XML Workshop : Utilizing Relational Data In XML Files
[font="Arial"]Matthew[/font]
April 24, 2014 at 2:51 am
Hi Matthew,
and thank you for this article.
Few comments, firstly the sp_xml_preparedocument and sp_xml_removedocument have some limitations and quite an overhead, I'm very hesitant recommending / implementing them on a production system. XQuery on the XML data type is without those limitations and in terms of importing XML data, only bound by the 2Gb size limit of the XML variable.
Secondly, the SQL Server uses UTF-16 as the encoding for the XML data type, casting from any other encoding will fail with an error. To bypass this, use OPENROWSET(BULK, [FILE_PATH], SINGLE_BLOB) without any typecast, to directly load the data into the destination table as this ignores any encoding specified in the source file.
Import example using XQuery:
USE tempdb;
GO
DECLARE @XMLTABLE TABLE
(
XML_ID INT IDENTITY(1,1) PRIMARY KEY CLUSTERED NOT NULL
,XML_DATA XML NOT NULL
);
INSERT INTO @XMLTABLE (XML_DATA)
SELECT BulkColumn FROM OPENROWSET
(
BULK
'C:\ImportXML\XMLDATA01.xml'
,SINGLE_BLOB
) AS IMPXML
UNION ALL
SELECT BulkColumn FROM OPENROWSET
(
BULK
'C:\ImportXML\XMLDATA02.xml'
,SINGLE_BLOB
) AS IMPXML
SELECT
XT.XML_ID
,PATI.ENT.value('id[1]' ,'INT') AS PATIENT_ID
,PATI.ENT.value('name[1]' ,'NVARCHAR(128)') AS PATIENT_NAME
,PATI.ENT.value('birthdate[1]','DATE') AS PATIENT_BIRTHDATE
FROM @XMLTABLE XT
OUTER APPLY XT.XML_DATA.nodes('root/patient') AS PATI(ENT);
😎
April 24, 2014 at 6:05 am
PowerShell is really a more efficient way to work with XML. Transact-SQL has never really been good at handling string data of any sort, and while XQuery is significantly better than OpenXML, PowerShell just runs circles around both of them.
I recently wrote an article demonstrating this at SQLMag.com.
http://sqlmag.com/powershell/use-powershell-load-xml-data-sql-server
Allen
April 24, 2014 at 6:57 am
It would be interesting to see the performance of PS when working with sets larger than the 2Gb limits of the XML data type. 😎
April 24, 2014 at 7:07 am
Wouldn't you have the same problem in Transact-SQL, though?
April 24, 2014 at 7:12 am
AllenMWhite (4/24/2014)
Wouldn't you have the same problem in Transact-SQL, though?
Yes of course, that is why I am interested in seeing how PS would handle this. Often had to implement all kinds of workarounds when the sets are tens or hundreds of Gbs.
😎
April 30, 2014 at 8:55 am
Nice article
I would add that OPENXML is not currently supported in an Azure SQL database, so if you're planning on migrating any time soon you'll want to stick with the XML data type. Given the overhead I've read about using OPENXML, I'm not sure this is something Microsoft ever plans on supporting.
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