Export SQL XML field to grid [duplicate] - sql

Question

I have something like the following XML in a column of a table:
<?xml version="1.0" encoding="utf-8"?>
<container>
<param name="paramA" value="valueA" />
<param name="paramB" value="valueB" />
...
</container>
I am trying to get the valueB part out of the XML via TSQL
So far I am getting the right node, but now I can not figure out how to get the attribute.
select xmlCol.query('/container/param[#name="paramB"]') from LogTable
I figure I could just add /#value to the end, but then SQL tells me attributes have to be part of a node. I can find a lot of examples for selecting the child nodes attributes, but nothing on the sibling atributes (if that is the right term).
Any help would be appreciated.

Answer 1

Try using the .value function instead of .query:
SELECT
xmlCol.value('(/container/param[#name="paramB"]/#value)[1]', 'varchar(50)')
FROM
LogTable
The XPath expression could potentially return a list of nodes, therefore you need to add a [1] to that potential list to tell SQL Server to use the first of those entries (and yes - that list is 1-based - not 0-based). As second parameter, you need to specify what type the value should be converted to - just guessing here.
Marc

Answer 2

Depending on the the actual structure of your xml, it may be useful to put a view over it to make it easier to consume using 'regular' sql eg
CREATE VIEW vwLogTable
AS
SELECT
c.p.value('#name', 'varchar(10)') name,
c.p.value('#value', 'varchar(10)') value
FROM
LogTable
CROSS APPLY x.nodes('/container/param') c(p)
GO
-- now you can get all values for paramB as...
SELECT value FROM vwLogTable WHERE name = 'paramB'