SQLite

We have seen how to store key-value data in the SharedPreferences class and more complex data in the form of files in either internal or external storage. But, if we want to store structured data, we should go for a database-like storage option. Android provides us with an implementation of SQLite we can use to store and query data.

Note

More information about SQLite is available at https://www.sqlite.org/. For more information on the SQLite applied to Android, refer to http://developer.android.com/training/basics/data-storage/databases.html.

Schema and contract definition

As a good practice, it is recommended that you define your database structure in a contract class. Doing it this way will make things very easy, for example, changing a column name and propagating all the changes to everywhere the database is used.

In addition to this, if we implement the BaseColumns interface, it will automatically add an _ID field, which we can use as the primary  autoincrement key.

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