SQL: querying specific value in column with XML Data - sql

Question

Boy, I've been researching this subject, but I am just not getting it. Sorry if I'm asking a question that has all ready been asked a million times, but its hard to understand when you're a noob like me, and the values in my tables aren't like the others I've seen. So here it goes...
In my SQL Server database, I have a table that has all my listings in it, called ItemsEbay.
The main identifier for each individual item has a column ID value called ItemID, so I would like to refer to that as needed.
Within that table is a column named ItemSpecifics that contains XML data.
Within the ItemSpecifics XML Data, is a node with a <Name> of UPC text and random value for that node:
What I would like, is a query that would allow me to search all the items in the ItemsEbay table that have a specific UPC value of my choosing, such as 1000100 or 10U100 for instance.
When I find the match values I'm querying, I would like to be able to replace them all at once with a new value Does Not Apply.

Answer 1

First of all: do not poste pictures!
What I've done here is your job: How to create a MCVE!
A dummy table with two rows, one contains the searched value, one doesn't
DECLARE #dummyTable TABLE(ID INT IDENTITY, ItemSpecifications XML);
INSERT INTO #dummyTable VALUES
(N'<SelectedValues>
<SelectedValue>
<Name>TestName</Name>
<Value>Xml1</Value>
</SelectedValue>
<SelectedValue>
<Name>UPC</Name>
<Value>123</Value><!--The UPC named value = 123 -->
</SelectedValue>
</SelectedValues>')
,(N'<SelectedValues>
<SelectedValue>
<Name>TestName</Name>
<Value>Xml2</Value>
</SelectedValue>
<SelectedValue>
<Name>UPC</Name>
<Value>999</Value><!--The UPC named value = 999 -->
</SelectedValue>
</SelectedValues>');
--I search for "123" and want to replace it with "SomeOther"
DECLARE #SearchFor VARCHAR(100)='123';
DECLARE #ReplaceWith VARCHAR(100)='SomeOther';
--The update statement uses .modify() for the XML change and .exist() to check for the search value below a <SelectedValue>, which <Name> element has a text() of "123":
UPDATE #dummyTable SET ItemSpecifications.modify(N'replace value of (/SelectedValues
/SelectedValue[(Name/text())[1]="UPC"]
/Value/text())[1]
with sql:variable("#ReplaceWith")')
WHERE ItemSpecifications.exist(N'/SelectedValues
/SelectedValue[(Name/text())[1]="UPC"]
/Value[text()=sql:variable("#SearchFor")]')=1;
--Check the result
SELECT * FROM #dummyTable;