sql xml xquery (4)

1,
DECLARE @myDoc xml
SET @myDoc = '<?Instructions for=TheWC.exe ?>
<Root>
<!-- instructions for the 1st work center -->
<Location LocationID="10"
LaborHours="1.1"
MachineHours=".2" >Some text 1
<step>Manufacturing step 1 at this work center</step>
<step>Manufacturing step 2 at this work center</step>
</Location>
</Root>'
SELECT @myDoc

-- delete an attribute
SET @myDoc.modify('
delete /Root/Location/@MachineHours
')
SELECT @myDoc

-- delete an element
SET @myDoc.modify('
delete /Root/Location/step[2]
')
SELECT @myDoc

-- delete text node (in <Location>
SET @myDoc.modify('
delete /Root/Location/text()
')
SELECT @myDoc

-- delete all processing instructions
SET @myDoc.modify('
delete //processing-instruction()
')
SELECT @myDoc

2,
use msdb

CREATE TABLE T (i int, x xml)
go
INSERT INTO T VALUES(1,'<Root>
<ProductDescription ProductID="1" ProductName="Road Bike">
<Features>
  <Warranty>1 year parts and labor</Warranty>
  <Maintenance>3 year parts and labor extended maintenance is available</Maintenance>
</Features>
</ProductDescription>
</Root>')
go
-- verify the contents before delete
SELECT x.query(' //ProductDescription/Features')
FROM T
-- delete the second feature
UPDATE T
SET x.modify('delete /Root/ProductDescription/Features/*[2]')
-- verify the deletion
SELECT x.query(' //ProductDescription/Features')
FROM T

DROP  TABLE  T