SQL Parse xml column data - sql

Question

I have very little experience with SQL Server. Here is what I am trying to accomplish:
I have a table with many rows. Every row contains a column named "Config". The data stored in the Config column is of the xml type. The xml structure looks like this:
<root>
<path1>
<path2>
<path3>true</path3>
</path2>
</path1>
</root>
I am trying to go through every row in the table and find the percentage of true to false values of <path3>.
I looked at some SQL documentation and tried to use the value() function I am having difficulties extracting the XML data from the column:
select Config.value('(/root/path1/path2/path3)[1]','nvarchar(max)') from [MyDB].[dbo].[MyTable]
Here is the result of my query:
I would like to query and extract data from the XML "Config" column of my table and aggregate that data into columns.

Answer 1

You need to specify namespaces in the query when xml is built with namespaces. For example
CREATE TABLE tbl (Config xml);
INSERT INTO tbl (Config)
VALUES ('<root xmlns="abc">
<path1>
<path2>
<path3>true</path3>
</path2>
</path1>
</root>') ;
Then
with xmlnamespaces (DEFAULT 'abc')
select Config.value('(/root/path1/path2/path3)[1]','nvarchar(max)') path3Txt
from tbl;
or explicit specification
with xmlnamespaces ('abc' as x)
select Config.value('(/x:root/x:path1/x:path2/x:path3)[1]','nvarchar(max)') path3Txt
from tbl;

Answer 2

You would need to use CROSS APPLY. Check it out.
SQL
-- DDL and sample data population, start
DECLARE #tbl TABLE (ID INT IDENTITY(1,1) PRIMARY KEY, [Config] XML);
INSERT INTO #tbl
VALUES (N'<root>
<path1>
<path2>
<path3>true</path3>
</path2>
</path1>
</root>')
, (N'<root>
<path1>
<path2>
<path3>false</path3>
</path2>
</path1>
</root>');
-- DDL and sample data population, end
;WITH rs AS
(
SELECT ID
, col.value('(./text())[1]','VARCHAR(20)') AS Result
FROM #tbl tbl
CROSS APPLY tbl.[Config].nodes('/root/path1/path2/path3') AS tab(col)
)
SELECT * FROM rs;