Learning Cypher电子书

Learning Cypher

Table of Contents

Learning Cypher

Credits

About the Author

About the Reviewers

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Preface

What this book covers

What you need for this book

Who this book is for

Conventions

Reader feedback

Customer support

Downloading the example code

Errata

Piracy

Questions

1. Querying Neo4j Effectively with Pattern Matching

Setting up a new Neo4j database

Neo4j running modes

Neo4j Server

An embedded database

Preparing the development environment

Creating an embedded database

Configuration

HR management tool – an example

Creating nodes and relationships using the Java API

A querying database

Invoking Cypher from Java

Finding nodes by relationships

Filtering properties

Filtering relationships

Dealing with missing parts

Working with paths

Node IDs as starting points

Query parameters

Passing parameters with Java

Summary

2. Filter, Aggregate, and Combine Results

Filtering

The book store – an example

Text search

Working with regular expressions

Escaping the text

Value comparisons

The IN predicate

Boolean operators

Working with collections

Paging results – LIMIT and SKIP

Sorting

A descending sort

Dealing with null values using the COALESCE function

Aggregating results

Counting matching rows or non-null values

Summation

Average

Maximum and minimum

Standard deviation

Collecting values in an array

Grouping keys

Conditional expressions

Separating query parts using WITH

The UNION statement

Summary

3. Manipulating the Database

Using Neo4j Browser

Creating nodes and relationships

Labels and properties

Multiple labels

Properties

Creating multiple patterns

Creating relationships

Creating full paths

Creating relationships between existing nodes using read-and-write queries

Modifying existing data

Creating unique patterns

Complex patterns

Setting properties and labels

Cloning a node

Adding labels to nodes

Merging matched patterns

Idempotent queries

Deleting data

Removing labels

Removing properties

Deleting nodes and relations

Clearing the whole database

Loops

Working with collections

Summary

4. Improving Performance

Performance issues

Best practices and recommendations

Using parameterized queries

Parameterized queries with the REST API

Reusing ExecutionEngine

Finding the optimum transaction size

Avoiding unnecessary clauses

Specifying the direction of relationships and variable length paths

Profiling queries

Profiling using the Java API

Inside the execution plan description

Profiling with Neo4j Shell

Profiling with the REST API

Indexes and constraints

SCAN hints

Index hints

Constraints

Summary

5. Migrating from SQL

Our example

Migrating the schema

Labels

Indexes and constraints

Relationships

Migrating the data

Entities

Relationships

Migrating queries

CRUD

Searching queries

Grouping queries

Summary

A. Operators and Functions

Operators

Comparison operators

Ordering operators

Equality operators

NULL equality operators

Mathematical operators

The concatenation operator

The IN operator

Regular expressions

Functions

COALESCE

TIMESTAMP

ID

Working with nodes

NODES

LABELS

Working with paths and relationships

TYPE

ENDNODE and STARTNODE

SHORTESTPATH and ALLSHORTESTPATHS

RELATIONSHIPS

Working with collections

HEAD, TAIL, and LAST

LENGTH

EXTRACT

FILTER

REDUCE

RANGE

Working with strings

SUBSTRING, LEFT, and RIGHT

STR

REPLACE

Trimming functions

LOWER and UPPER

Aggregation functions

COUNT

SUM

AVG

PERCENTILEDISC and PERCENTILECONT

STDEV and STDEVP

MIN and MAX

Mathematical functions

Index