Tag Archives: SQLXML

SQL Server XML Red Gate Ebook, XQuery Labs

Jacob Sebastian is a SQL Server XML Guru!

Check out his collection for XQUery Labs. This is the first 12 of his series, and right now he has 43 and counting:

XQuery Sample Scripts

* XQuery Lab 1 – Transforming rows to columns
* XQuery Lab 2 – An example using OUTER APPLY
* XQuery Lab 3 – Filtering specific nodes
* XQuery Lab 4 – Joining XML Nodes with a Relational Table
* XQuery Lab 5 – Working with Namespaces
* XQuery Lab 6 – Processing Header-Detail information
* XQuery Lab 7 – Extracting a comma separated list of values
* XQuery Lab 8 – How to update the attribute value of an XML variable?
* XQuery Lab 9 – How to delete an attribute from an XML variable?
* XQuery Lab 10 – How to insert an attribute to an XML variable
* XQuery Lab 11 – How to insert an element to an XML variable
* XQuery Lab 12 – Different ways of reading values from an XML variable

Jacob Sebastian has also released a free ebook via RedGate – The Art of XSD – SQL Server XML Schema Collections

Check it out, all 483 pages! 🙂

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SQLXML : How to Work With XML Elements (or Nodes) in SQL Server

Assume this is your XML snippet
[sql collapse=”false” firstline=”1″ gutter=”true” smarttabs=”true” tabsize=”4″ toolbar=”true”]

DECLARE @authorsXML XML

SET @authorsXML = ‘
<Author>
<ID>172-32-1176</ID>
<LastName>White</LastName>
<FirstName>Johnson</FirstName>
<Address>
<Street>10932 Bigge Rd.</Street>
<City>Menlo Park</City>
<State>CA</State>
</Address>
</Author>

[/sql]

Note that the examples below show how you can manipulate XML nodes – but most operations require singleton values. Ie, the changes must affect one and only one node. Thus in most the examples we specify the index of the node we want to target.

For example:

[sql collapse=”false” firstline=”1″ gutter=”false” smarttabs=”true” tabsize=”4″ toolbar=”false”]

(/Author/LastName)[1]

[/sql]

which means we are only targetting the first instance of LastName under the Author node. If you need to do a mass update, you may need to use a cursor.

Read more

SQLXML : How to Alter Existing Column Schema (XSD)

Sometimes you may need to change schema definitions in existing columns.

The following shows an example of how you can do this:

   1: -- drop the XML schema from existing column definitions
   2: ALTER TABLE AD
   3:    ALTER COLUMN Title xml
   4:  
   5: -- DROP IF EXISTS
   6: IF    EXISTS (SELECT name 
   7:               FROM  sys.xml_schema_collections 
   8:               WHERE name='TitleSchema')
   9:    DROP  XML SCHEMA COLLECTION TitleSchema
  10: GO
  11:  
  12: -- new definition
  13: -- there can only be one Title element
  14: CREATE XML SCHEMA COLLECTION TitleSchema AS 
  15: '<?xml version="1.0" encoding="utf-8"?>
  16: <xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  17:   <xsd:element name="Title">
  18:     <xsd:complexType>
  19:          <xsd:attribute name="Type" type="xsd:string" />
  20:          <xsd:attribute name="Value" type="xsd:string" use="optional" />
  21:     </xsd:complexType>
  22:   </xsd:element>
  23: </xsd:schema>'
  24: GO
  25:  
  26: -- IMPORTANT: before you add back the schema to the column 
  27: -- definition, make sure all values in your existing column 
  28: -- comply with the new schema definition
  29: ALTER TABLE AD
  30:    ALTER COLUMN Title xml(TitleSchema)

SQLXML : How to List Columns That Have the XML Data Type

   1: -- this lists the table catalog, table name, 
   2: -- column name, and data type
   3: SELECT 
   4:     TABLE_CATALOG,
   5:     TABLE_NAME,
   6:     COLUMN_NAME, 
   7:     DATA_TYPE 
   8: FROM 
   9:     INFORMATION_SCHEMA.COLUMNS
  10: WHERE 
  11:     DATA_TYPE = 'xml'
  12:  

 

   1: -- this lists the corresponding schemas
   2: SELECT 
   3:     DISTINCT
   4:     OBJECT_NAME(sys.columns.object_id)        AS 'TableName',
   5:     sys.columns.name                    AS 'ColName',
   6:     sys.xml_schema_collections.name            AS 'Schema' 
   7: FROM 
   8:     sys.columns
   9:     LEFT JOIN     sys.xml_schema_collections 
  10:     ON sys.columns.xml_collection_id = sys.xml_schema_collections.xml_collection_id
  11: ORDER BY 
  12:     OBJECT_NAME(sys.columns.object_id), sys.columns.name    
  13:  

SQLXML : How to List Schema Elements and Attributes

   1: SELECT
   2:     sys.xml_schema_collections.xml_collection_id    AS CollectionID,
   3:     sys.xml_schema_collections.name                 AS SchemaName,
   4:     sys.xml_schema_elements.name                    AS ElementName,
   5:     sys.xml_schema_attributes.name                  AS AttributeName
   6: FROM
   7:     sys.xml_schema_collections
   8:     INNER JOIN sys.xml_schema_attributes
   9:     ON sys.xml_schema_collections.xml_collection_id =  sys.xml_schema_attributes.xml_collection_id
  10:     INNER JOIN sys.xml_schema_elements
  11:     ON sys.xml_schema_collections.xml_collection_id = sys.xml_schema_elements.xml_collection_id
  12: WHERE
  13:     sys.xml_schema_collections.name NOT LIKE 'sys'

Sample Result:

SQLXML Sample Result - Elements and Attribute Names

SQLXML : How to Create an XML Schema

The following is an example of how to create an XML Schema in SQL Server.

   1: -- DROP IF EXISTS
   2: IF    EXISTS (SELECT 1 
   3:               FROM  sys.xml_schema_collections 
   4:               WHERE name='SampleSchema')
   5:    DROP XML SCHEMA COLLECTION SampleSchema
   6:  
   7: CREATE XML SCHEMA COLLECTION SampleSchema AS 
   8: '<?xml version="1.0" encoding="utf-8"?>
   9: <xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  10:   <xsd:element name="Sample">
  11:     <xsd:complexType>
  12:       <xsd:attribute name="SampleID" type="xsd:integer" />
  13:       <xsd:attribute name="Name" type="xsd:string" />
  14:       <xsd:attribute name="Description" type="xsd:string" />
  15:     </xsd:complexType>
  16:   </xsd:element>
  17: </xsd:schema>'

 

To check your XML Schema:

Method 1: Go to your database > Programmability > Types > XML Schema Collections

SQLXML - XML Schema Collection

Method 2: You can use the xml_schema_namespace function to query the schema from within SSMS

   1:  
   2: SELECT
   3:    xml_schema_namespace(N'dbo',N'SampleSchema') 

 

Later on I will post additional sample schemas which use different SQL XML data types.

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