XML Schema Collection (SQL Server 2012): How to create an XML Schema Collection that can be used to Validate a field name (column title) of an existing dbo Table of a Database in SSMS2012?

Question

Hi all,
I used the following code to create a new Database (ScottChangDB) and a new Table (marvel) in my SQL Server 2012 Management Studio (SSMS2012) successfully:
-- ScottChangDB.sql saved in C://Documents/SQL Server XQuery_MacLochlainns Weblog_code
-- 14 April 2015 09:15 AM
USE master
IF EXISTS
(SELECT 1
FROM sys.databases
WHERE name = 'ScottChangDB')
DROP DATABASE ScottChangDB
GO
CREATE DATABASE ScottChangDB
GO
USE ScottChangDB
CREATE TABLE [dbo].[marvel] (
[avenger_name] [char] (30) NULL, [ID] INT NULL)
INSERT INTO marvel
(avenger_name,ID)
VALUES
('Hulk', 1),
('Iron Man', 2),
('Black Widow', 3),
('Thor', 4),
('Captain America', 5),
('Hawkeye', 6),
('Winter Soldier', 7),
('Iron Patriot', 8);
SELECT avenger_name FROM marvel ORDER BY ID For XML PATH('')
DECLARE @x XML
SELECT @x=(SELECT avenger_name FROM marvel ORDER BY ID FOR XML PATH('Marvel'))--,ROOT('root'))
SELECT
person.value('Marvel[4]', 'varchar(100)') AS NAME
FROM @x.nodes('.') AS Tbl(person)
ORDER BY NAME DESC
--Or if you want the completed element
SELECT @x.query('/Marvel[4]/avenger_name')
DROP TABLE [marvel]
Now I am trying to create my first XML Schema Collection to do the Validation on the Field Name (Column Title) of the "marvel" Table. I have studied Chapter 4 XML SCHEMA COLLECTIONS of the book "Pro SQL Server 2008 XML" written by
Michael Coles (published by Apress) and some beginning pages of XQuery Language Reference, SQL Server 2012 Books ONline (published by Microsoft). I mimicked  Coles' Listing 04-05 and I wanted to execute the following first-drafted sql in
my SSMS2012:
-- Reference [Scott Chang modified Listing04-05.sql of Pro SQL Server 2008 XML by Michael Coles (Apress)]
-- [shcColes04-05.sql saved in C:\\Documents\XML_SQL_Server2008_code_Coles_Apress]
-- [executed: 2 April 2015 15:04 PM]
-- shcXMLschemaTableValidate1.sql in ScottChangDB of SQL Server 2012 Management Studio (SSMS2012)
-- saved in C:\Documents\XQuery-SQLServer2012
tried to run: 15 April 2015 ??? AM
USE ScottChangDB;
GO
CREATE XML SCHEMA COLLECTION dbo. ComplexTestSchemaCollection_all
AS
N'<?xml version="1.0"?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<xsd:element name="marvel">
<xsd:complexType>
<xsd:all>
<xsd:element name="avenger_name" />
<xsd:element name="ID" />
</xsd:all>
</xsd:complexType>
</xsd:element>
</xsd:schema>';
GO
DECLARE @x XML (dbo. ComplexTestSchemaCollection_all);
SET @x = N'<?xml version="1.0"?>
<marvel>
<avenger_name>Thor</name>
<ID>4</ID>
</marvel>';
SELECT @x;
GO
DROP XML SCHEMA COLLECTION dbo.ComplexTestSchemaCollection_all;
GO
I feel that drafted sql is very shaky and it needs the SQL Server XML experts to modify to make it work for me. Please kindly help, exam the coding of my shcXMLTableValidate1.sql and modify it to work.
Thanks in advance,
Scott Chang

Answer 1

Hi Scott,
2) Yes, FOR XML PATH clause converts relational data to XML format with a specific structure for the "marvel" Table. Regarding validate all the avenger_names, please see below
sample.
DECLARE @x XML
SELECT @x=(SELECT ID ,avenger_name FROM marvel FOR XML PATH('Marvel'))
SELECT @x
SELECT
n.value('avenger_name[1]','VARCHAR(99)') avenger_name,
n.value('ID[1]','INT') ID
FROM @x.nodes('//Marvel') Tab(n)
WHERE n.value('ID[1]','INT') = 1 -- specify the ID here
--FOR XML PATH('Marvel')  --uncommented this line if you want the result as element type
3)i.check the xml schema content
--find xml schema collection
SELECT ss.name,xsc.name collection_name FROM sys.xml_schema_collections xsc JOIN sys.schemas ss ON xsc.schema_id= ss.schema_id
select * from sys.schemas
--check the schema content,use the name,collection_name from the above query
SELECT xml_schema_namespace(N'name',N'collection_name')
3)ii. View can be viewed as virtual table. Use a view to list the XML schema content.
CREATE VIEW XSDContentView
AS
SELECT ss.name,xsc.name collection_name,cat.content
FROM sys.xml_schema_collections xsc JOIN sys.schemas ss ON xsc.schema_id= ss.schema_id
CROSS APPLY(
SELECT xml_schema_namespace(ss.name,xsc.name) AS content
) AS cat
WHERE xsc.name<>'sys'
GO
SELECT * FROM XSDContentView
By the way, it would be appreciated if you can spread your questions into posts. For any question, feel free to let me know.
Eric Zhang
TechNet Community Support