Select XML nodes as rows

Question

I am selecting from a table that has an XML column using T-SQL. I would like to select a certain type of node and have a row created for each one.

For instance, suppose I am selecting from a people table. This table has an XML column for addresses. The XML is formated similar to the following:

<address>
  <street>Street 1</street>
  <city>City 1</city>
  <state>State 1</state>
  <zipcode>Zip Code 1</zipcode>
</address>
<address>
  <street>Street 2</street>
  <city>City 2</city>
  <state>State 2</state>
  <zipcode>Zip Code 2</zipcode>
</address>

How can I get results like this:

Name         City         State

Joe Baker   Seattle      WA

Joe Baker   Tacoma     WA

Fred Jones  Vancouver BC

Answer 1

If you can use it, the linq api is convenient for XML:

var addresses = dataContext.People.Addresses
    .Elements("address")
        .Select(address => new { 
            street  = address.Element("street").Value, 
            city    = address.Element("city").Value, 
            state   = address.Element("state").Value, 
            zipcode = address.Element("zipcode").Value, 
        });

Answer 2

http://www.setfocus.com/technicalarticles/sql-server-2005-xml.aspx

There are a few suggestions on how to do it here, but all of them appear heavily dependant on knowing the XML schema beforehand.

Answer 3

Here is your solution:

/* TEST TABLE */
DECLARE @PEOPLE AS TABLE ([Name] VARCHAR(20),  [Address] XML )
INSERT INTO @PEOPLE SELECT 
    'Joel', 
    '<address>
      <street>Street 1</street>
      <city>City 1</city>
      <state>State 1</state>
      <zipcode>Zip Code 1</zipcode>
    </address>
    <address>
      <street>Street 2</street>
      <city>City 2</city>
      <state>State 2</state>
      <zipcode>Zip Code 2</zipcode>
    </address>'
UNION ALL SELECT
    'Kim', 
    '<address>
      <street>Street 3</street>
      <city>City 3</city>
      <state>State 3</state>
      <zipcode>Zip Code 3</zipcode>
    </address>'

SELECT * FROM @PEOPLE

-- BUILD XML
DECLARE @x XML
SELECT @x = 
( SELECT 
      [Name]
    , [Address].query('
            for $a in //address
            return <address 
                street="{$a/street}" 
                city="{$a/city}" 
                state="{$a/state}" 
                zipcode="{$a/zipcode}" 
            />
        ') 
  FROM @PEOPLE AS people 
  FOR XML AUTO
) 

-- RESULTS
SELECT [Name]    = T.Item.value('../@Name', 'varchar(20)'),
       street    = T.Item.value('@street' , 'varchar(20)'),
       city      = T.Item.value('@city'   , 'varchar(20)'),
       state     = T.Item.value('@state'  , 'varchar(20)'),
       zipcode   = T.Item.value('@zipcode', 'varchar(20)')
FROM   @x.nodes('//people/address') AS T(Item)

/* OUTPUT*/

Name | street   | city   | state   | zipcode
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Joel | Street 1 | City 1 | State 1 | Zip Code 1
Joel | Street 2 | City 2 | State 2 | Zip Code 2
Kim  | Street 3 | City 3 | State 3 | Zip Code 3

Answer 4

Here's how I do it generically:

I shred the source XML via a call such as

DECLARE @xmlEntityList xml
SET @xmlEntityList =
'
<ArbitrarilyNamedXmlListElement>
        <ArbitrarilyNamedXmlItemElement><SomeVeryImportantInteger>1</SomeVeryImportantInteger></ArbitrarilyNamedXmlItemElement>
        <ArbitrarilyNamedXmlItemElement><SomeVeryImportantInteger>2</SomeVeryImportantInteger></ArbitrarilyNamedXmlItemElement>
        <ArbitrarilyNamedXmlItemElement><SomeVeryImportantInteger>3</SomeVeryImportantInteger></ArbitrarilyNamedXmlItemElement>
</ArbitrarilyNamedXmlListElement>
'

    DECLARE @tblEntityList TABLE(
     SomeVeryImportantInteger int
    )

    INSERT @tblEntityList(SomeVeryImportantInteger)
    SELECT 
     XmlItem.query('//SomeVeryImportantInteger[1]').value('.','int') as SomeVeryImportantInteger
    FROM
     [dbo].[tvfShredGetOneColumnedTableOfXmlItems] (@xmlEntityList)

by utilizing the scalar-valued function

/* Example Inputs */
/*
DECLARE @xmlListFormat xml
SET  @xmlListFormat =
      '
      <ArbitrarilyNamedXmlListElement>
        <ArbitrarilyNamedXmlItemElement>004421UB7</ArbitrarilyNamedXmlItemElement>
        <ArbitrarilyNamedXmlItemElement>59020UH24</ArbitrarilyNamedXmlItemElement>
        <ArbitrarilyNamedXmlItemElement>542514NA8</ArbitrarilyNamedXmlItemElement>
      </ArbitrarilyNamedXmlListElement>
      '
declare @tblResults TABLE 
(
    XmlItem xml
)

*/

-- =============================================
-- Author:   6eorge Jetson
-- Create date: 01/02/3003
-- Description: Shreds a list of XML items conforming to
--     the expected generic @xmlListFormat
-- =============================================
CREATE FUNCTION [dbo].[tvfShredGetOneColumnedTableOfXmlItems]  
(
    -- Add the parameters for the function here
    @xmlListFormat xml
)
RETURNS 
@tblResults TABLE 
(
    -- Add the column definitions for the TABLE variable here
    XmlItem xml
)
AS
BEGIN

    -- Fill the table variable with the rows for your result set
    INSERT @tblResults
    SELECT
     tblShredded.colXmlItem.query('.') as XmlItem
    FROM
      @xmlListFormat.nodes('/child::*/child::*') as tblShredded(colXmlItem)

    RETURN 
END

--SELECT * FROM @tblResults