Talend Open Studio Cookbook

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Talend Open Studio Cookbook

Credits

About the Author

About the Reviewers

www.PacktPub.com

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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

Chapter 1. Introduction and General Principles

Before you begin

Installing the software

Enabling tHashInput and tHashOutput

Chapter 2. Metadata and Schemas

Introduction

Hand-cranking a built-in schema

Propagating schema changes

Creating a generic schema from the existing metadata

Cutting and pasting schema information

Dropping schemas to empty components

Creating schemas from lists

Chapter 3. Validating Data

Introduction

Enabling and disabling reject flows

Gathering all rejects prior to killing a job

Validating against the schema

Rejecting rows using tMap

Checking a column against a list of allowed values

Checking a column against a lookup

Creating validation rules for more complex requirements

Creating binary error codes to store multiple test results

Chapter 4. Mapping Data

Introduction

Simple mapping and tMap time savers

Creating tMap expressions

Using the ternary operator for conditional logic

Using intermediate variables in tMap

Filtering input rows

Splitting an input row into multiple outputs based on input conditions

Joining data using tMap

Hierarchical joins using tMap

Using reload at each row to process real-time / near real-time data

Chapter 5. Using Java in Talend

Introduction

Performing one-off pieces of logic using tJava

Setting the context and globalMap variables using tJava

Adding complex logic into a flow using tJavaRow

Creating pseudo components using tJavaFlex

Creating custom functions using code routines

Importing JAR files to allow use of external Java classes

Chapter 6. Managing Context Variables

Introduction

Creating a context group

Adding a context group to your job

Adding contexts to a context group

Using tContextLoad to load contexts

Using implicit context loading to load contexts

Turning implicit context loading on and off in a job

Setting the context file location in the operating system

Chapter 7. Working with Databases

Introduction

Setting up a database connection

Importing the table schemas

Reading from database tables

Using context and globalMap variables in SQL queries

Printing your input query

Writing to a database table

Printing your output query

Managing database sessions

Passing a session to a child job

Selecting different fields and keys for insert update and delete

Capturing individual rejects and errors

Database and table management

Managing surrogate keys for parent and child tables

Rewritable lookups using an in-process database

Chapter 8. Managing Files

Introduction

Appending records to a file

Reading rows using a regular expression

Using temporary files

Storing intermediate data in the memory using tHashMap

Reading headers and trailers using tMap

Reading headers and trailers with no identifiers

Using the information in the header and trailer

Adding a header and trailer to a file

Moving copying renaming and deleting files and folders

Capturing file information

Processing multiple files at once

Processing control/validation files

Creating and writing files depending on the input data

Chapter 9. Working with XML Queues and Web Services

Introduction

Using tXMLMap to read XML

Using tXMLMap to create an XML document

Reading complex hierarchical XML