Book Image

Groovy 2 Cookbook

Book Image

Groovy 2 Cookbook

Overview of this book

Get up to speed with Groovy, a language for the Java Virtual Machine (JVM) that integrates features of both object-oriented and functional programming. This book will show you the powerful features of Groovy 2 applied to real-world scenarios and how the dynamic nature of the language makes it very simple to tackle problems that would otherwise require hours or days of research and implementation. Groovy 2 Cookbook contains a vast number of recipes covering many facets of today's programming landscape. From language-specific topics such as closures and metaprogramming, to more advanced applications of Groovy flexibility such as DSL and testing techniques, this book gives you quick solutions to everyday problems. The recipes in this book start from the basics of installing Groovy and running your first scripts and continue with progressively more advanced examples that will help you to take advantage of the language's amazing features. Packed with hundreds of tried-and-true Groovy recipes, Groovy 2 Cookbook includes code segments covering many specialized APIs to work with files and collections, manipulate XML, work with REST services and JSON, create asynchronous tasks, and more. But Groovy does more than just ease traditional Java development: it brings modern programming features to the Java platform like closures, duck-typing, and metaprogramming. In this new book, you'll find code examples that you can use in your projects right away along with a discussion about how and why the solution works. Focusing on what's useful and tricky, Groovy 2 Cookbook offers a wealth of useful code for all Java and Groovy programmers, not just advanced practitioners.
Table of Contents (17 chapters)
Groovy 2 Cookbook
About the Authors
About the Reviewers

Modifying data in an SQL database

The logical step after querying a database (see the Querying an SQL database recipe) is writing data to it. This recipe shows how a few lines of Groovy and very little boilerplate is needed to do the job of modifying data in a database table.

Getting ready

This recipe also uses the same table structure and the way to start a database server defined in the Creating a database table recipe.

How to do it...

As usual, create a new Groovy script named modifyDb.groovy. As for the previous recipes, in this case we also need to import the DBUtil class.

  1. Add the following code to the newly created script:

    import static DBUtil.*
    import groovy.sql.Sql
    def server = startServer()
  2. The next logical step is to define the initial data to write to the database. Add the following code to the script, a variable containing a list of Maps with the data to persist:

    def cookbooks = [
      [ id: 1,
        title: '30-minute-meals',
        author: 'Jamie Oliver',
        year: 2010],