How to parse XML column in SQL Server 2012? - sql-server

Question

I have never used XML parsing in SQL Server, I would like to extract the fields in its own column, get the correct data.
I have a column called CustomerHeaderUncompressed in a Customer table that looks something like below, how do I extract the fields and the data in SQL Server 2012?
<CustomerHeaderData>
<CustomerHeader>
<shippingmethod Value="00000000-0000-0000-0000-000000000000" Name="" />
<discount Value="" />
<customdiscount Value="0" />
<ponumber Value="9909933793" />
<tax1 Value="-1" />
<tax2 Value="-1" />
<tax3 Value="0" />
<tax3name Value="" />
<tax4 Value="0" />
<Freight />
<ClientExtraField6 Value="5" />
<ClientExtraField7 Value="3" />
<dateneeded Value="01/01/0001 00:00:00" />
<ClientTaxCodeSource>0</ClientTaxCodeSource>
<shippingbranch />
<dropnumber Value="" />
<comment Value="" />
<shippingzone Value="" />
<salespersonID Value="704e78d4-cdbb-4963-bcc2-2c83a1d5f3fd" />
<salesperson Value="Salesrep, XYZ" />
<installation Value="False" />
<salesterms Value="18" />
<HeldItemDeliveryMethod Value="0" />
<customcontrol>
<CustomCustomerHeader CultureInfo="en-US">
<BusinessSegment>TR</BusinessSegment>
<BusinessSegmentID>1</BusinessSegmentID>
<OrderType>2</OrderType>
<MarketSegment>S3</MarketSegment>
<CustomerDeliveryDate>2010-01-21</CustomerDeliveryDate>
<BuildingPermitNumber />
<FinalWallDepth />
<PricingType>2</PricingType>
<HouseBuiltBefore1978>False</HouseBuiltBefore1978>
<AttributePricing>False</AttributePricing>
<UndeterminedAttributes>False</UndeterminedAttributes>
<EventIDStatus>VerifyFailed</EventIDStatus>
<EventIDEnabled>False</EventIDEnabled>
<CustomerDiscount>0</CustomerDiscount>
<PreparedBy />
<RequestedShipDate>01/14/2010</RequestedShipDate>
<UserTestDate>01/01/0001</UserTestDate>
</CustomCustomerHeader>
</customcontrol>
</CustomerHeader>

Answer 1

Basically something like this:
select from your Customer table
use CROSS APPLY and the XQuery .nodes() function to grab the XML as a "on-the-fly" pseudo table of XML fragments (table alias XT, single column aliassed as XC)
"reach" into those XML fragments and pull out the values you need, using the .value() XQuery function; use element names as such, and attributes need to be prefixed with a # sign
Try this and extend it to your needs:
SELECT
ShippingMethodValue = XC.value('(shippingmethod/#Value)[1]', 'varchar(50)'),
ShippingMethodName = XC.value('(shippingmethod/#Name)[1]', 'varchar(50)'),
DiscountValue = XC.value('(discount/#Value)[1]', 'varchar(50)'),
CustomDiscountValue = XC.value('(customdiscount/#Value)[1]', 'varchar(50)'),
PONumber= XC.value('(ponumber/#Value)[1]', 'bigint' )
FROM
Customer
CROSS APPLY
CustomerHeaderUncompressed.nodes('/CustomerHeaderData/CustomerHeader') AS XT(XC)