Xquery

by Walmsley, Priscilla

• ISBN13: 9780596006341
• ISBN10: 0596006349
• Format: Paperback
• Copyright: 2007-04-01
• Publisher: Oreilly & Associates Inc

Summary

With the XQuery 1.0 language, database developers finally have a tool that will make it much easier to exchange information between XML and relational data sources. This in- depth tutorial not only walks them through the XQuery specification, but also teaches them how to program with this widely-anticipated language. Whether database developers are coming from SQL, XSLT, or starting from scratch, they will learn about XQuery's support for filtering, sorting, and grouping data, as well as how to use FLWR expressions, XPath, and XQuery tools for extracting and combining information. Readers will discover how to apply all of these tools to a wide variety of data sources, and how to recombine information from multiple sources into a single final output result. "XQuery" also delves into critical advanced issues such as data typing and designing efficient query logic.

Table of Contents

Preface

Introduction to XQuery

What Is XQuery?

Easing into XQuery

Path Expressions

FLWORs

Adding XML Elements and Attributes

FunctionsJoins

Aggregating and Grouping Values

XQuery Foundations

The Design of the XQuery LanguageX

Query in Context

Processing Queries

The XQuery Data Model

TypesNamespaces

Expressions: XQuery Building Blocks

Categories of Expressions

Keywords and Names

Whitespace in QueriesLiterals

Variables

Function Calls

Comments

Evaluation Order and Parentheses

Comparison Expressions

Conditional (if-then-else) Expressions

Logical (and/or) Expressions

Navigating Input Documents Using Paths

Path ExpressionsPredicates

Dynamic Paths

Input Documents

A Closer Look at Context

Adding Elements and Attributes to Results

Including Elements and Attributes from the Input Document

Direct Element Constructors

Computed Constructors

Selecting and Joining Using FLWORs

Selecting with Path Expressions

FLWOR Expressions

Quantified Expressions

Selecting Distinct Values

Joins

Sorting and Grouping

Sorting in XQuery

Grouping

Aggregating Values

Functions

Built-in Versus User-Def ined Functions

Calling Functions

User-Defined Functions

Advanced Queries

Copying Input Elements with Modifications

Working with Positions and Sequence Numbers

Combining Results

Using Intermediate XML Documents

Namespaces and XQuery

XML Namespaces

Namespaces and XQuery

Namespace Declarations in Queries

Controlling Namespace Declarations in Your Results

A Closer Look at Types

The XQuery Type System

The Built-in Types

Types, Nodes, and Atomic Values

Type Checking in XQuery

Automatic Type Conversions

Sequence Types

Constructors and Casting

Queries, Prologs, and Modules

Structure of a Query: Prolog and Body

Assembling Queries from Multiple Modules

Variable Declarations

Declaring External Functions

Using Schemas with XQuery

What Is a Schema?

Why Use Schemas with Queries?W3C XML Schema: A Brief Overview

In-Scope Schema Definitions

Schema Validation and Type Assignment

Sequence Types and Schemas

Static Typing

What Is Static Typing?

The Typeswitch Expression

The Treat Expression

Type Declarations

The zero-or-one, one-or-more, and exactly-one Functions

Principles of Query Design

Query Design Goals

Clarity

Modularity

RobustnessError Handling

Performance

Working with Numbers

The Numeric Types

Constructing Numeric Values

Comparing Numeric Values

Arithmetic Operations

Functions on Numbers

Working with Strings

The xs:string Type

Constructing Strings

Comparing Strings

Substrings

Finding the Length of a String

Concatenating and Splitting Strings

Manipulating Strings

Whitespace and Strings

Internationalization Considerations

Regular Expressions

The Structure of a Regular Expression

Representing Individual Characters

Representing Any Character

Representing Groups of Characters

Character Class Expressions

Reluctant Quantifiers

AnchorsBack-References

Using FlagsUsing Sub-Expressions with Replacement Variables

Working with Dates, Times, and Durations

The Date and Time Types

The Duration Types

Extracting Components of Dates, Times, and Durations

Using Arithmetic Operators on Dates, Times, and Durations

The Date Component Types

Working with Qualified Names, URIs, and IDs

Working with Qualified Names

Working with URIs

Working with IDs

Working with Other XML Components

XML Comments

Processing Instructions

Documents

Text Nodes

XML Entity and Character References

CDATA Sections

Additional XQuery-Related Standards

SerializationXQueryXXQuery Update Facility

Full-Text SearchXQuery API for Java (XQJ)

Implementation-Specific Features

ConformanceXML Version Support

Setting the Query Context

Option Declarations and Extension Expressions

Specifying Serialization Parameters

XQuery for SQL Users

Relational Versus XML Data Models

Comparing SQL Syntax with XQuery Syntax

Combining SQL and XQuerySQL/XML

XQuery for XSLT UsersXQuery and XPathXQuery Versus XSLT

Differences Between XQuery 1.0/XPath 2.0 and XPath 1.0

Built-in Function Reference

Built-in Types

Error Summary

Index

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