module 3: using xml

Module 3:Using XML

Overview

Retrieving XML by Using FOR XML

Shredding XML by Using OPENXML

Introducing XQuery

Using the xml Data Type

Lesson 1: Retrieving XML by Using FOR XML

Introduction to the FOR XML Clause

What Are RAW Mode Queries?

What Are AUTO Mode Queries?

What Are EXPLICIT Mode Queries?

What Are PATH Mode Queries?

Syntax for Retrieving Nested XML

Practice: Using FOR XML

Introduction to the FOR XML Clause

Extends SELECT syntax

Returns XML instead of rows and columns

Configurable to return attributes, elements, and schema

Benefits client applications that work with XML

Converted to XMLConverted to XML

Client ApplicationClient ApplicationDatabase ServerDatabase Server

<row CustID="1" CustomerType="S" SalesOrderID="43860"/><row CustID="1" CustomerType="S" SalesOrderID="44501"/>...

<row CustID="1" CustomerType="S" SalesOrderID="43860"/><row CustID="1" CustomerType="S" SalesOrderID="44501"/>...

SELECT Cust.CustomerID CustID, CustomerType, SalesOrderIDFROM Customer Cust JOIN SalesOrderHeader [Order] ON Cust.CustomerID = [Order].CustomerIDORDER BY Cust.CustomerIDFOR XML RAW

SELECT Cust.CustomerID CustID, CustomerType, SalesOrderIDFROM Customer Cust JOIN SalesOrderHeader [Order] ON Cust.CustomerID = [Order].CustomerIDORDER BY Cust.CustomerIDFOR XML RAW

SELECT Cust.CustomerID CustID, CustomerType, SalesOrderIDFROM Customer Cust JOIN SalesOrderHeader [Order] ON Cust.CustomerID = [Order].CustomerIDORDER BY Cust.CustomerIDFOR XML RAW, ELEMENTS

SELECT Cust.CustomerID CustID, CustomerType, SalesOrderIDFROM Customer Cust JOIN SalesOrderHeader [Order] ON Cust.CustomerID = [Order].CustomerIDORDER BY Cust.CustomerIDFOR XML RAW, ELEMENTS

<row><CustID>1</CustID><CustomerType>S</CustomerType><SalesOrderID>43860</SalesOrderID>

</row>...

<row><CustID>1</CustID><CustomerType>S</CustomerType><SalesOrderID>43860</SalesOrderID>

</row>...

SELECT Cust.CustomerID CustID, CustomerType, SalesOrderIDFROM Customer Cust JOIN SalesOrderHeader [Order] ON Cust.CustomerID = [Order].CustomerIDORDER BY Cust.CustomerIDFOR XML RAW('Order'), ROOT('Orders')

SELECT Cust.CustomerID CustID, CustomerType, SalesOrderIDFROM Customer Cust JOIN SalesOrderHeader [Order] ON Cust.CustomerID = [Order].CustomerIDORDER BY Cust.CustomerIDFOR XML RAW('Order'), ROOT('Orders')

<Orders><Order><CustID>1</CustID><CustomerType>S</...</Order>...

</Orders>

<Orders><Order><CustID>1</CustID><CustomerType>S</...</Order>...

</Orders>

What Are RAW Mode Queries?

XML representation of a rowsetXML representation of a rowset

Contains either elements or attributesContains either elements or attributes

Optional root element and row element nameOptional root element and row element name

What Are AUTO Mode Queries?

XML representation of data entities

Nest data based on join precedence

Can use options such as ELEMENTS and ROOT

SELECT Cust.CustomerID CustID, CustomerType, SalesOrderIDFROM Customer Cust JOIN SalesOrderHeader [Order] ON Cust.CustomerID = [Order].CustomerIDORDER BY Cust.CustomerIDFOR XML AUTO

SELECT Cust.CustomerID CustID, CustomerType, SalesOrderIDFROM Customer Cust JOIN SalesOrderHeader [Order] ON Cust.CustomerID = [Order].CustomerIDORDER BY Cust.CustomerIDFOR XML AUTO

<Cust CustID="1" CustomerType="S"><Order SalesOrderID="43860" /><Order SalesOrderID="44501" />...

</Cust><Cust CustID="2" CustomerType="S">...

<Cust CustID="1" CustomerType="S"><Order SalesOrderID="43860" /><Order SalesOrderID="44501" />...

</Cust><Cust CustID="2" CustomerType="S">...

SELECT 1 AS Tag, NULL AS Parent, SalesOrderID AS [Invoice!1!InvoiceNo], OrderDate AS [Invoice!1!Date!Element]FROM SalesOrderHeader FOR XML EXPLICIT


What Are EXPLICIT Mode Queries?

<Invoice InvoiceNo="43659"><Date>2001-07-01T00:00:00</Date>

</Invoice><Invoice InvoiceNo="43660">...



Tabular representations of XML documentsTabular representations of XML documents

Allow complete control of XML formatAllow complete control of XML format

ElementElement

AttributeAttribute







Tag Parent Invoice!1!InvoiceNo Invoice!1!Date!Element

1 NULL 43659 2001-07-01T00:00:00

1 NULL 43660 2001-07-02T00:00:00

What Are PATH Mode Queries?

Use XPath to specify XML format

Allow creation of nested data

Easier to use than EXPLICIT mode

SELECT EmployeeID "@EmpID", FirstName "EmpName/First", LastName "EmpName/Last"FROM Person.Contact INNER JOIN Employee

ON Person.Contact.ContactID = Employee.ContactIDFOR XML PATH

SELECT EmployeeID "@EmpID", FirstName "EmpName/First", LastName "EmpName/Last"FROM Person.Contact INNER JOIN Employee

ON Person.Contact.ContactID = Employee.ContactIDFOR XML PATH

<row EmpID="1"><EmpName>

<First>Guy</First><Last>Gilbert</Last>

</EmpName></row>...

<row EmpID="1"><EmpName>

<First>Guy</First><Last>Gilbert</Last>

</EmpName></row>...

Syntax for Retrieving Nested XML

AUTO mode produces only attributes or elementsAUTO mode produces only attributes or elements

Use inner FOR XML with TYPE clause to return xml data typeUse inner FOR XML with TYPE clause to return xml data type

Combine EXPLICIT mode with UNION ALLCombine EXPLICIT mode with UNION ALL

<Cust CustomerID="1" CustomerType="S"><Order SalesOrderID="43860" Status="5"/><Order SalesOrderID="44501" Status="5"/>...

</Cust>

<Cust CustomerID="1" CustomerType="S"><Order SalesOrderID="43860" Status="5"/><Order SalesOrderID="44501" Status="5"/>...

</Cust>

SELECT Cust.CustomerID, CustomerType, SalesOrderID, Status

FROM Customer Cust JOIN SalesOrderHeader [Order]ON Cust.CustomerID = [Order].CustomerID

ORDER BY Cust.CustomerIDFOR XML AUTO



ORDER BY Cust.CustomerIDFOR XML AUTO



ORDER BY Cust.CustomerIDFOR XML AUTO, ELEMENTS



ORDER BY Cust.CustomerIDFOR XML AUTO, ELEMENTS

<Cust><CustomerID>1</CustomerID><CustomerType>S</CustomerType><Order>

<SalesOrderID>43860</SalesOrderID><Status>5</Status>...

<Cust><CustomerID>1</CustomerID><CustomerType>S</CustomerType><Order>

<SalesOrderID>43860</SalesOrderID><Status>5</Status>...

SELECT Name CategoryName,(SELECT Name SubCategoryNameFROM ProductSubCategory SubCategoryWHERE SubCategory.ProductCategoryID =

Category.ProductCategoryIDFOR XML AUTO, TYPE, ELEMENTS)

FROM ProductCategory CategoryFOR XML AUTO

SELECT Name CategoryName,(SELECT Name SubCategoryNameFROM ProductSubCategory SubCategoryWHERE SubCategory.ProductCategoryID =

Category.ProductCategoryIDFOR XML AUTO, TYPE, ELEMENTS)

FROM ProductCategory CategoryFOR XML AUTO

<Category CategoryName="Accessories"><SubCategory>

<SubCategoryName>Bike Racks</SubCategoryName></SubCategory>...

<Category CategoryName="Accessories"><SubCategory>

<SubCategoryName>Bike Racks</SubCategoryName></SubCategory>...

<Invoice InvoiceNo="43659"><Date>2001-07-01T00:00:00</Date><LineItem ProductID="709">Bike Socks, M</LineItem><LineItem ProductID="711">Helmet, Blue</LineItem>

</Invoice>...

<Invoice InvoiceNo="43659"><Date>2001-07-01T00:00:00</Date><LineItem ProductID="709">Bike Socks, M</LineItem><LineItem ProductID="711">Helmet, Blue</LineItem>

</Invoice>...

SELECT 1 AS Tag, NULL AS Parent, ...FROM SalesOrderHeaderUNION ALLSELECT 2 AS Tag, 1 AS Parent, ...FROM SalesOrderDetail OD JOIN ...FOR XML EXPLICIT

SELECT 1 AS Tag, NULL AS Parent, ...FROM SalesOrderHeaderUNION ALLSELECT 2 AS Tag, 1 AS Parent, ...FROM SalesOrderDetail OD JOIN ...FOR XML EXPLICIT

Practice: Using FOR XML

In this practice, you will:

Retrieve XML in RAW mode

Retrieve XML in AUTO mode

Retrieve XML in EXPLICIT mode

Retrieve XML in PATH mode

Lesson 2: Shredding XML by Using OPENXML

Overview of Shredding XML Data

Stored Procedures for Managing In-Memory Node Trees

OPENXML Syntax

Syntax for Working With XML Namespaces

Practice: Using OPENXML to Shred XML

XML documentreceived from clientXML documentreceived from client

11

Overview of Shredding XML Data

Use OPENXML to retrieve rowsetUse OPENXML to retrieve rowset

33

Use sp_xml_removedocumentto clean up memory treeUse sp_xml_removedocumentto clean up memory tree55

Create internal tree representation by using sp_xml_preparedocument

Create internal tree representation by using sp_xml_preparedocument

22

Process (or shred) the data into tablesProcess (or shred) the data into tables

44

Stored Procedures for Managing In-Memory Node Trees

Create tree by using sp_xml_preparedocument

Free memory by using sp_xml_removedocument

CREATE PROC ProcessOrder @doc xml -- xml data

AS

-- Declare document handleDECLARE @hdoc integer

-- Create memory treeEXEC sp_xml_preparedocument @hdoc OUTPUT, @doc

-- Process Document

-- Remove memory treeEXEC sp_xml_removedocument @hdoc

CREATE PROC ProcessOrder @doc xml -- xml data

AS

-- Declare document handleDECLARE @hdoc integer

-- Create memory treeEXEC sp_xml_preparedocument @hdoc OUTPUT, @doc

-- Process Document

-- Remove memory treeEXEC sp_xml_removedocument @hdoc

OPENXML Syntax

<Customer CustomerID="1" CustomerType="S"> <Order SalesOrderID="43860" Status="5" OrderDate="2001-08-01T00:00:00"> <OrderDetail ProductID="761" Quantity="2"/> <OrderDetail ProductID="770" Quantity="1"/> </Order></Customer>

<Customer CustomerID="1" CustomerType="S"> <Order SalesOrderID="43860" Status="5" OrderDate="2001-08-01T00:00:00"> <OrderDetail ProductID="761" Quantity="2"/> <OrderDetail ProductID="770" Quantity="1"/> </Order></Customer>

SELECT *FROM OPENXML (@idoc, '/Customer/Order/OrderDetail', 1)WITH (CustomerID int '../../@CustomerID', OrderID int '../@SalesOrderID', OrderDate datetime '../@OrderDate', ProdID int '@ProductID', Quantity int)

SELECT *FROM OPENXML (@idoc, '/Customer/Order/OrderDetail', 1)WITH (CustomerID int '../../@CustomerID', OrderID int '../@SalesOrderID', OrderDate datetime '../@OrderDate', ProdID int '@ProductID', Quantity int)

From Order element

From Order element

From Customer element

From Customer element

Uses attributes as defaultUses attributes as defaultrowpattern identifies node levelrowpattern identifies node level

Defaults to Quantity attributeDefaults to Quantity attribute From OrderDetail elementFrom OrderDetail element

Syntax for Working With XML Namespaces

sp_xml_preparedocument accepts namespaces

Use namespace prefix in all XPath expressions

<Customer xmlns="urn:AW_NS" xmlns:o="urn:AW_OrderNS" CustomerID="1" CustomerType="S">

<o:Order SalesOrderID="43860" Status="5" OrderDate="2001-08-01T00:00:00"> <o:OrderDetail ProductID="761" Quantity="2"/> <o:OrderDetail ProductID="770" Quantity="1"/> </o:Order></Customer>

EXEC sp_xml_preparedocument @idoc OUTPUT, @doc, <ROOT xmlns:rootNS="urn:AW_NS" xmlns:orderNS="urn:AW_OrderNS"/>'

SELECT * FROM OPENXML (@idoc, '/rootNS:Customer/orderNS:Order/orderNS:OrderDetail')WITH...

<Customer xmlns="urn:AW_NS" xmlns:o="urn:AW_OrderNS" CustomerID="1" CustomerType="S">

<o:Order SalesOrderID="43860" Status="5" OrderDate="2001-08-01T00:00:00"> <o:OrderDetail ProductID="761" Quantity="2"/> <o:OrderDetail ProductID="770" Quantity="1"/> </o:Order></Customer>

EXEC sp_xml_preparedocument @idoc OUTPUT, @doc, <ROOT xmlns:rootNS="urn:AW_NS" xmlns:orderNS="urn:AW_OrderNS"/>'

SELECT * FROM OPENXML (@idoc, '/rootNS:Customer/orderNS:Order/orderNS:OrderDetail')WITH...

Practice: Using OPENXML to Shred XML


Use the OPENXML function

Shred XML by using elements only

Shred XML by using attributes or elements

Shred XML by using a colpattern parameter

Lesson 3: Introducing XQuery

What Is XQuery?

XQuery Basics

XQuery Expressions

What Is XQuery?

Query language to identify nodes in XMLQuery language to identify nodes in XML

/InvoiceList/Invoice[@InvoiceNo=1000]/InvoiceList/Invoice[@InvoiceNo=1000]

FLWOR statementsFLWOR statements

Statement Descriptionfor Iterate through sibling nodes

where Apply filtering criteria to the iteration

order by Sort values in returned resultset

return Specify the XML to be returned

Sequences and QNamesSequences and QNames

XQuery Basics

Result of an XQuery expression is a sequence

All identifiers are QNames

Result of an XQuery expression is a sequence

All identifiers are QNames

OperatorsOperators

Arithmetic comparison

General comparison

Value comparison

Node comparison

Node order comparison

Logical

Arithmetic comparison

General comparison

Value comparison

Node comparison

Node order comparison

Logical

CommentsComments

(: Comment text :) (: Comment text :)

if-then-elseif-then-else

if ( $A eq $B )then <result>A</result>else <result>B</result>

if ( $A eq $B )then <result>A</result>else <result>B</result>

Path expressionsPath expressions

XQuery Expressions

RelativeRelative

Primary expressionsPrimary expressions

Literals

Variable references

Function calls

Literals

Variable references

Function calls

Sequence expressionsSequence expressions

Construct, filter and combine sequencesConstruct, filter and combine sequences declare @x xml

set @x = '<root><abc></abc><abc attrAbc="1"></abc><abc attrAbc="2"></abc></root>'SELECT

@x.query('/root/abc[attrAbc]')

declare @x xmlset @x = '<root><abc></abc><abc attrAbc="1"></abc><abc attrAbc="2"></abc></root>'SELECT

@x.query('/root/abc[attrAbc]')

child::Address/child::Country child::Address/child::Country

AbsoluteAbsolute

/Address/Country /Address/Country

Lesson 4: Using the xml Data Type

What Is the xml Data Type?

The query, value, and exist Methods

The modify Method

The nodes Method

Practice: Using the xml Data Type

What Is the xml Data Type?

Native data type for XML

Internal storage structure for XML InfoSet

Use for tables, variables, or parameters

Exposes methods to query and modify XML

-- usage within table definitionCREATE TABLE NewTable( Col1 int primary key,

Col2 xml )

-- usage as local variabledeclare @data xml

-- usage as parameter to stored procedureCREATE PROCEDURE SaveData(@doc xml) AS ...

-- usage within table definitionCREATE TABLE NewTable( Col1 int primary key,

Col2 xml )

-- usage as local variabledeclare @data xml

-- usage as parameter to stored procedureCREATE PROCEDURE SaveData(@doc xml) AS ...

The query, value, and exist Methods

SELECT xmlCol.query( '<InvoiceNumbers> { for $i in /InvoiceList/Invoice return <InvoiceNo> {number($i/@InvoiceNo)} </InvoiceNo> } </InvoiceNumbers>')

SELECT xmlCol.query( '<InvoiceNumbers> { for $i in /InvoiceList/Invoice return <InvoiceNo> {number($i/@InvoiceNo)} </InvoiceNo> } </InvoiceNumbers>')

SELECT xmlCol.value('(/InvoiceList/Invoice/@InvoiceNo)[1]', 'int')

SELECT xmlCol.value('(/InvoiceList/Invoice/@InvoiceNo)[1]', 'int')

SELECT xmlCol.exist('/InvoiceList/Invoice[@InvoiceNo=1000]')

SELECT xmlCol.exist('/InvoiceList/Invoice[@InvoiceNo=1000]')

SELECT Invoices.query( '<Store> {sql:column("StoreName")} </Store>')

SELECT Invoices.query( '<Store> {sql:column("StoreName")} </Store>')

Use query to return untyped XMLUse query to return untyped XML

Use value to return a scalar valueUse value to return a scalar value

Bind relational columns and variablesBind relational columns and variables

Use exist to check for the existence of a specified valueUse exist to check for the existence of a specified value

The modify Method

SET @xmlDoc.modify( 'insert element salesperson {"Bill"} as first into (/InvoiceList/Invoice)[1]')

SET @xmlDoc.modify( 'insert element salesperson {"Bill"} as first into (/InvoiceList/Invoice)[1]')

SET xmlCol.modify( replace value of(/InvoiceList/Invoice/SalesPerson/text())[1] with "Ted"')

SET xmlCol.modify( replace value of(/InvoiceList/Invoice/SalesPerson/text())[1] with "Ted"')

SET @xmlDoc.modify( 'delete (/InvoiceList/Invoice/SalesPerson)[1]')

SET @xmlDoc.modify( 'delete (/InvoiceList/Invoice/SalesPerson)[1]')

insert adds child nodes or siblings to an XML documentinsert adds child nodes or siblings to an XML document

replace value of updates a node in the XML documentreplace value of updates a node in the XML document

delete removes a node from the XML documentdelete removes a node from the XML document

The nodes Method

SELECT nCol.value('@ProductID', 'int') Product,

nCol.value('@Quantity', 'int') QtyFROM @xmlOrder.nodes('/Order/LineItem')AS nTable(nCol)

SELECT nCol.value('@ProductID', 'int') Product,

nCol.value('@Quantity', 'int') QtyFROM @xmlOrder.nodes('/Order/LineItem')AS nTable(nCol)

SELECT nCol.value('../@OrderID[1]', 'int') ID, nCol.value('@ProductID[1]', 'int') ProdFROM Orders CROSS APPLY OrderDoc.nodes('/Order/LineItem') AS nTable(nCol)

SELECT nCol.value('../@OrderID[1]', 'int') ID, nCol.value('@ProductID[1]', 'int') ProdFROM Orders CROSS APPLY OrderDoc.nodes('/Order/LineItem') AS nTable(nCol)

Shreds xml variables into relational dataShreds xml variables into relational data

Requires the APPLY operator with xml columnsRequires the APPLY operator with xml columns

Practice: Using the xml Data Type


Use the xml data type

Use the query, value, and exist methods

Bind relational columns

Use the modify method to insert, update, and delete XML

Use the nodes method

Lab: Working With XML

Exercise 1: Mapping Relational Data and XML

Exercise 2: Storing XML Natively in the Database

Exercise 3: Using XQuery With xml Methods

module 3: using xml

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