How to transform XML data into SQL Server Table

Question

I have a XML data like this :

<root>
 <log realm="ABC" at="Wed Oct 15 00:00:02 2014.211" lifespan="2279ms">
  <receive>
    <isomsg direction="IN">
      <header>6000911384</header>
      <field id="0" value="0800"/>
      <field id="3" value="980000"/>
      <field id="11" value="000852"/>
    </isomsg>
  </receive>
</log>
</root>

how can I transform that XML data into table like this :

    AT         |lifespan|direction |ID |Value 
---------------------------------------------
Wed Oct 15 2014|2279ms  |in        |0  |0800
Wed Oct 15 2014|2279ms  |in        |3  |980000
Wed Oct 15 2014|2279ms  |in        |11 |000852

Answer 1

This would be a lot easier than @Nick's answer, since it only needs one .nodes() call instead of three nested ones...

DECLARE @input XML = '<root>
 <log realm="ABC" at="Wed Oct 15 00:00:02 2014.211" lifespan="2279ms">
  <receive>
    <isomsg direction="IN">
      <header>6000911384</header>
      <field id="0" value="0800"/>
      <field id="3" value="980000"/>
      <field id="11" value="000852"/>
    </isomsg>
  </receive>
</log>
</root>'

SELECT
    At = xc.value('../../../@at', 'varchar(50)'),
    Lifespan = xc.value('../../../@lifespan', 'varchar(25)'),
    Direction = xc.value('../@direction', 'varchar(10)'),
    ID = XC.value('@id', 'int'),
    Value = xc.value('@value', 'varchar(25)')
FROM
    @Input.nodes('/root/log/receive/isomsg/field') AS XT(XC)

The call to @Input.nodes basically returns a "virtual" table of XML fragments, representing each of the <field> XML elements. By using the .. we can also navigate "up the" XML hierarchy in the original document to access the <isomsg> and <log> elements and grab attribute values from those