Almost finishing these series of XML workshop, really helped a lot.
The proposal of adding FOR XML EXPLICIT, ROOT('CustomersByRegion') works for me too, I'm using SQL 2008R2
Again in this post the links to the code are broken.
Here is the code with comments in spanish.
--=================================================================================================================================
-- XML Workshop Part IV: usando EXPLICIT
/*EXPLICIT es mucho más complicado de usar que la sintaxis FOR XML (AUTO/RAW/PATH) pero por otra parte permite un control
muy detallado sobre el XML que se quiere generar. Al usar EXPLICIT la query resultante debe tener una estructura
determinada, que se configura mediante varios modificadores en la query misma (TAG, PARENT,...)
*/
--=================================================================================================================================
--vamos a intentar reproducir el mismo XML que usamos en el WorkShop 3
/*
<customersByRegion>
<country name="USA" currency="US Dollars">
<city name="NY">
<customer id="MK" name="John Mark" phone="111-111-1111"/>
<customer id="WS" name="Will Smith" phone="222-222-2222"/>
</city>
<city name="NJ">
<customer id="EN" name="Elizabeth Lincoln" phone="333-333-3333"/>
</city>
</country>
<country name="England" currency="Pound Sterling">
<city name="London">
<customer id="TH" name="Thomas Hardy" phone="444-444-4444"/>
</city>
</country>
<country name="India" currency="Rupees">
<city name="New Delhi">
<customer id="JS" name="Jacob Sebastian" phone="555-555-5555"/>
</city>
</country>
</customersByRegion>
*/
/*
vamos a generar en un primer paso el nodo Country del XML
prestar atención a los modificadore TAG y PARENT.
TAG: esta columna es obligada, informa al generador del XML el nivel del elemento en la jerarquía del XML que queremos obtener
en el ejemplo tenemos "1" que significa que este será el nodo principal del XML
Parent: es la 2da columna obligada. Dice al generador XML cual será el nodo padre del elemento seleccionado.
en el ejemplo es NULL ya que Country no tiene nodo padre
'Country!1!name' : "Country" es el nombre del elemento
"1" especifica el nivel del nodo
"name" es el nombre del atributo
'Country!1!currency' : igual que con Country, tenemos que Country es el nombre del elemento, "1" su nivel y "currency" el atributo
*/
SELECT 1 AS Tag,
NULL AS Parent,
c.CountryName AS 'Country!1!name',
c.Currency AS 'Country!1!currency'
FROM Countries c
/*
veamos que tenemos en el nodo City
prestar atención a:
TAG tiene valor 2, para hacer corresponder la jerarquía en el XML que queremos como resultado
PARENT tiene valor 1 para hacer corresponder con el tag parent superior, que sería Country
*/
SELECT 2 AS Tag,
1 AS Parent,
Country.CountryName,
Country.Currency,
City.CityName
FROM Cities City
INNER JOIN Countries Country ON (Country.CountryID = City.CountryID)
--el resultado lo uniremos con lo que tenemos para el nodo Country
SELECT 1 AS Tag,
NULL AS Parent,
c.CountryName AS 'Country!1!name',
c.Currency AS 'Country!1!currency',
NULL AS 'City!2!name'
FROM Countries c
UNION ALL
SELECT 2 AS Tag,
1 AS Parent,
Country.CountryName,
Country.Currency,
City.CityName
FROM Cities City
INNER JOIN Countries Country ON (Country.CountryID = City.CountryID)
ORDER BY 'Country!1!name', 'City!2!name'
FOR XML EXPLICIT
/*
so far so good...añadiremos ahora el nodo Customer, siguiendo la misma filosofía de usar el UNION ALL
al igual que antes prestar atención a los valores de TAG y PARENT, 3 y 2 respectivamente para hacer la correspondencia
con el elemento City
*/
SELECT
1 AS Tag,
NULL AS Parent,
c.CountryName AS 'Country!1!name',
c.Currency AS 'Country!1!currency',
NULL AS 'City!2!name',
NULL AS 'Customer!3!id',
NULL AS 'Customer!3!name',
NULL AS 'Customer!3!phone'
FROM
Countries c
UNION ALL
SELECT
2 AS Tag,
1 AS Parent,
Country.CountryName,
Country.Currency,
City.CityName,
NULL,
NULL,
NULL
FROM Cities City
INNER JOIN Countries Country ON (Country.CountryID = City.CountryID)
UNION ALL
SELECT
3 AS Tag,
2 AS Parent,
Country.CountryName AS [name],
Country.Currency,
City.CityName AS [name],
Customer.CustomerNumber AS [id],
Customer.CustomerName AS [name],
Customer.Phone
FROM
Customers Customer
INNER JOIN Cities City ON (City.CityID = Customer.CityID)
INNER JOIN Countries Country ON (Country.CountryID = City.CountryID)
ORDER BY 'Country!1!name', 'City!2!name'
FOR XML EXPLICIT
/*
Aún falta por añadir el elemento root. Para lograrlo añadiremos un elemento padre superior con todos los campos a NULL
y solo el campo TAG=1, modificando todos los demás valores de TAG para tener la correspondencia correcta
*/
SELECT 1 AS Tag,
NULL AS Parent,
NULL AS 'CustomersByRegion!1', -- empty root element
NULL AS 'Country!2!name',
NULL AS 'Country!2!currency',
NULL AS 'City!3!name',
NULL AS 'Customer!4!id',
NULL AS 'Customer!4!name',
NULL AS 'Customer!4!phone'
UNION ALL
SELECT
2 AS Tag,
1 AS Parent,
NULL,
c.CountryName AS 'Country!1!name',
c.Currency AS 'Country!1!currency',
NULL AS 'City!2!name',
NULL AS 'Customer!3!id',
NULL AS 'Customer!3!name',
NULL AS 'Customer!3!phone'
FROM
Countries c
UNION ALL
SELECT
3 AS Tag,
2 AS Parent,
NULL,
Country.CountryName,
Country.Currency,
City.CityName,
NULL,
NULL,
NULL
FROM Cities City
INNER JOIN Countries Country ON (Country.CountryID = City.CountryID)
UNION ALL
SELECT
4 AS Tag,
3 AS Parent,
NULL,
Country.CountryName AS [name],
Country.Currency,
City.CityName AS [name],
Customer.CustomerNumber AS [id],
Customer.CustomerName AS [name],
Customer.Phone
FROM
Customers Customer
INNER JOIN Cities City ON (City.CityID = Customer.CityID)
INNER JOIN Countries Country ON (Country.CountryID = City.CountryID)
ORDER BY 'Country!2!name', 'City!3!name', Parent
FOR XML EXPLICIT