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If you only occasionally dabble in XML and XPath utilizing the XML data type in SQL Server can be a bit daunting. I found it very useful in passing parameters to stored procedures containing object graphs. The same can be accomplished the table parameter if you only have a list of one type of objects, but if you need to pass an object graph of parent/child objects of different types, using XML will be your best bet.

Below I demonstrate how one could represent a list of Contact objects in an XML document and subsequently access the data via a select statement. the @Contacts parameter could be used as a parameter to a stored procedure if you’re running SQL 2005 or higher. Use your imagination for the rest.

declare @Contacts xml

set @Contacts = 
    '<root>
    <Contact>
        <ContactID>1</ContactID>
        <Email>contact1@contact1.com</Email>
    </Contact>
    <Contact>
        <ContactID>2</ContactID>
        <Email>contact2@contact2.com</Email>
    </Contact>
    <Contact>
        <ContactID>3</ContactID>
        <Email>contact3@contact3.com</Email>
    </Contact>
    </root>'


select
    ContactID = Contact.value('ContactID[1]', 'int'),
    Email = Contact.value('Email[1]', 'varchar(255)')
from
    @Contacts.nodes('root/Contact') as Contacts([Contact])

Posted on January 3, 2011 at 10:35 am in T-SQL   |  RSS feed |   Reply   |   Trackback URL