Book Image

Android Programming with Kotlin for Beginners

By : John Horton
5 (1)
Book Image

Android Programming with Kotlin for Beginners

5 (1)
By: John Horton

Overview of this book

Android is the most popular mobile operating system in the world and Kotlin has been declared by Google as a first-class programming language to build Android apps. With the imminent arrival of the most anticipated Android update, Android 10 (Q), this book gets you started building apps compatible with the latest version of Android. It adopts a project-style approach, where we focus on teaching the fundamentals of Android app development and the essentials of Kotlin by building three real-world apps and more than a dozen mini-apps. The book begins by giving you a strong grasp of how Kotlin and Android work together before gradually moving onto exploring the various Android APIs for building stunning apps for Android with ease. You will learn to make your apps more presentable using different layouts. You will dive deep into Kotlin programming concepts such as variables, functions, data structures, Object-Oriented code, and how to connect your Kotlin code to the UI. You will learn to add multilingual text so that your app is accessible to millions of more potential users. You will learn how animation, graphics, and sound effects work and are implemented in your Android app. By the end of the book, you will have sound knowledge about significant Kotlin programming concepts and start building your own fully featured Android apps.
Table of Contents (33 chapters)
Android Programming with Kotlin for Beginners
Contributors
Preface
Index

The Android SQLite API


There are a number of different ways in which the Android API makes it fairly easy to use our app's database. The first class we need to get familiar with is SQLiteOpenHelper.

SQLiteOpenHelper and SQLiteDatabase

The SQLiteDatabase class is the class that represents the actual database. The SQLiteOpenHelper class, however, is where most of the action takes place. This class will enable us to get access to a database and initialize an instance of SQLiteDatabase.

In addition, the SQLiteOpenHelper class, which we will inherit from in our Age database app, has two functions to override. First, it has an onCreate function, which is called the first time a database is used, and it therefore makes sense that we would incorporate our SQL in which to create our table structure.

The other function we must override is onUpgrade, which, you can probably guess, is called when we upgrade our database (ALTER its structure).

Building and executing queries

As our database structures become...