android development beyond the basics

Android DevelopmentBeyond the Basics

S.Vanjikumaran

Saving the Data

● Most Android apps need to save data!! even if only to save information about the app state during onPause() so the user's progress is not lost.

● Most non-trivial apps also need to save user settings, and some apps must manage large amounts of information in files and databases.

Saving Key-Value Sets

● If you have a relatively small collection of key-values that you'd like to save, you should use the SharedPreferences APIs.

Saving Files

● Android uses a file system that's similar to disk-based file systems on other platforms. This lesson describes how to work with the Android file system to read and write files with the File APIs.

Saving Data in SQL Database

● Saving data to a database is ideal for repeating or structured data, such as contact information. This class assumes that you are familiar with SQL databases in general and helps you get started with SQLite databases on Android. The APIs you'll need to use a database on Android are available in the android.database.sqlite package.

What is SQLite?

● SQLite is an Open Source Database● supports standard relational database

features● It requires only little memory at runtime● SQLite supports the data types

SQLite in Android

● SQLite is available on every Android device● SQLite database in android does not require

any database setup

SQLite Architecture

SQL 101

● DML● DDL

First Ever Database in Android

● What you need to know?○ android.database.sqlite package

●

First Ever Database in Android

● Defines the table name and column names for a single table

First Ever Database in Android

● Create a Database Using a SQL Helper

First Ever Database in Android

● Insert data into the database by passing a ContentValues object to the insert() method

First Ever Database in Android

● Read Information from a Database

First Ever Database in Android

● When you need to modify a subset of your database values, use the update() method.