Extracting Values From Two-Level XML List Into SQL Column

Question

I have an SQL server 2008 database from which I am extracting multiple values from various tables to put into a single table. Among these values is some data pulled from XML that until recently was stored on a single level like so:

<XMLData>
  <Item>
    <Name>Name1</Name>
    <Value>Value1</Value>
  </Item>
  <Item>
    <Name>Name2</Name>
    <Value>Value2</Value>
  </Item>
  <Item>
    <Name>Name3</Name>
    <Value>Value3</Value>
  </Item>
  <Item>
    <Name>Name4</Name>
    <Value>Value4</Value>
  </Item>
</XMLData>

I would extract the necessary information with the following method:

SELECT
   Name = IXML.value('(./Name)[1]', 'varchar(20)'),
   Value = IXML.value('(./Value)[1]', 'varchar(20)')
INTO dbo.newTable
FROM dbo.oldTable
CROSS APPLY oldTable.InfoXML.nodes('/XMLData/item') Book(IXML)

Which would return:

Name    Value
--------------
Name1   Value1
Name2   Value2
Name3   Value3
Name4   Value4

However, now the XML list has been altered and is generated within another list like so:

<XMLData>
<LongDirectory>
  <Category>
    <Item>
      <CategoryName>Cat1</CategoryName>
      <SubCategory>
        <Item>
          <Name>Name1</Name>
          <Value>Value1</Value>
        </Item>
        <Item>
          <Name>Name2</Name>
          <Value>Value2</Value>
        </Item>
        <Item>
          <Name>Name3</Name>
          <Value>Value3</Value>
        </Item>
      </SubCategory>
    </Item>
    <Item>
      <CategoryName>Cat2</CategoryName>
      <SubCategory>
        <Item>
          <Name>Name4</Name>
          <Value>Value4</Value>
        </Item>
        <Item>
          <Name>Name5</Name>
          <Value>Value5</Value>
        </Item>
      </SubCategory>
    </Item>
    <Item>
      <CategoryName>Cat3</CategoryName>
      <SubCategory>
        <Item>
          <Name>Name6</Name>
          <Value>Value6</Value>
        </Item>
        <Item>
          <Name>Name7</Name>
          <Value>Value7</Value>
        </Item>
      </SubCategory>
    </Item>
  </Category>
</LongDirectory>
</XMLData>

And I need to generate the information to look like this:

Name    Value    Category
-------------------------
Name1   Value1   Cat1
Name2   Value2   Cat1
Name3   Value3   Cat1
Name4   Value4   Cat2
Name5   Value5   Cat2
Name6   Value6   Cat3
Name7   Value7   Cat3

How would I go about modifying my query to accommodate the change in structure? Any help is appreciated.

Answer 1

You can do it with nested nodes() methods:

select
    I.C.value('(Name)[1]', 'varchar(20)') as Name,
    I.C.value('(Value)[1]', 'varchar(20)') as Value,
    C.C.value('(CatName)[1]', 'varchar(20)') as Category
-- into dbo.newTable
from dbo.oldTable as T
    cross apply T.InfoXML.nodes('XMLData/Category') as C(C)
    cross apply C.C.nodes('Item') as I(C)

Or use parent axis (..):

select
    I.C.value('(Name)[1]', 'varchar(20)') as Name,
    I.C.value('(Value)[1]', 'varchar(20)') as Value,
    I.C.value('(../CatName)[1]', 'varchar(20)') as Category
-- into dbo.newTable
from dbo.oldTable as T
    cross apply T.InfoXML.nodes('XMLData/Category/Item') as I(C)

sql fiddle example

---

update:

select
    I.C.value('(Name)[1]', 'varchar(20)') as Name,
    I.C.value('(Value)[1]', 'varchar(20)') as Value,
    C.C.value('(CategoryName)[1]', 'varchar(20)') as Category
from dbo.oldTable as T
    outer apply T.InfoXML.nodes('XMLData/LongDirectory/Category/Item') as C(C)
    outer apply C.C.nodes('SubCategory/Item') as I(C)

sql fiddle example