How to get value from a node in XML via SQL Server - sql

Question

I've found several pieces of information online about this but I can't get it working for the life of me.
This is the XML I have:
I need to extract the ID & Name value for each node. There are a lot.
I tried to do this but it returns NULL:
select [xml].value('(/Alter/Object/ObjectDefinition/MeasureGroup/Partitions/Partition/ID)[1]', 'varchar(max)')
from test_xml
I understand the above would return only 1 record. My question is, how do I return all records?
Here's the XML text (stripped down version):
<Alter xmlns="http://schemas.microsoft.com/analysisservices/2003/engine" AllowCreate="true" ObjectExpansion="ExpandFull">
<ObjectDefinition>
<MeasureGroup xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<ID>ts_homevideo_sum_20140430_76091ba1-3a51-45bf-a767-f9f3de7eeabe</ID>
<Name>table_1</Name>
<StorageMode valuens="ddl200_200">InMemory</StorageMode>
<ProcessingMode>Regular</ProcessingMode>
<Partitions>
<Partition>
<ID>123</ID>
<Name>2012</Name>
</Partition>
<Partition>
<ID>456</ID>
<Name>2013</Name>
</Partition>
</Partitions>
</MeasureGroup>
</ObjectDefinition>
</Alter>

Answer 1

You need something like this:
DECLARE #MyTable TABLE (ID INT NOT NULL, XmlData XML)
INSERT INTO #MyTable (ID, XmlData)
VALUES (1, '<Alter xmlns="http://schemas.microsoft.com/analysisservices/2003/engine" AllowCreate="true" ObjectExpansion="ExpandFull">
<ObjectDefinition>
<MeasureGroup xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<ID>ts_homevideo_sum_20140430_76091ba1-3a51-45bf-a767-f9f3de7eeabe</ID>
<Name>table_1</Name>
<StorageMode valuens="ddl200_200">InMemory</StorageMode>
<ProcessingMode>Regular</ProcessingMode>
<Partitions>
<Partition>
<ID>123</ID>
<Name>2012</Name>
</Partition>
<Partition>
<ID>456</ID>
<Name>2013</Name>
</Partition>
</Partitions>
</MeasureGroup>
</ObjectDefinition>
</Alter>')
;WITH XMLNAMESPACES(DEFAULT 'http://schemas.microsoft.com/analysisservices/2003/engine')
SELECT
tbl.ID,
MeasureGroupID = xc.value('(ID)[1]', 'varchar(200)'),
MeasureGroupName = xc.value('(Name)[1]', 'varchar(200)'),
PartitionID = xp.value('(ID)[1]', 'varchar(200)'),
PartitionName = xp.value('(Name)[1]', 'varchar(200)')
FROM
#MyTable tbl
CROSS APPLY
tbl.XmlData.nodes('/Alter/ObjectDefinition/MeasureGroup') AS XT(XC)
CROSS APPLY
XC.nodes('Partitions/Partition') AS XT2(XP)
WHERE
ID = 1
First of all, you must respect and include the default XML namespace defined in the root of your XML document.
Next, you need to do a nested call to .nodes() to get all <MeasureGroup> and all contained <Partition> nodes, so that you can reach into those XML fragments and extract the ID and Name from them.
This should then result in something like this as output: