![]() The second int argument is the new (upgrade) database version. The first int argument is the current (installed) database version. ![]() Note also that the OnUpgrade() method additionally accepts two int arguments. Note that both methods take a SQLiteDatabase argument. Your OnUpgrade() method should contain the code to amend your database when you make subsequent changes to the database structure. Your OnCreate() method should contain all the code necessary to create your database entities such as tables and indexes. OnUpgrade() is invoked when you upgrade your application. ![]() OnCreate() is invoked when your application is installed for the first time.Within your newly created subclass, you will need to provide implementations for the methods OnCreate() and OnUpgrade(). This is an Android helper class for managing database creation and versioning. To create a database with SQLite, you will need to create a subclass of SQLiteOpenHelper. Provide an implementation for the virtual method OnUpgrade().Provide an implementation for the virtual method OnCreate().The following code shows a skeletal example of how your database is created and updated within Android. Using SQLite Creating and Updating Your Database To include Sqlite functionality in your application, you will need to add the following reference to your code: This article demonstrates one way in which you can use Sqlite in your own Xamarin.Android application, but it is certainly not the only one. For this reason, it is a good idea to consider performing such tasks asynchronously.Īs with any database tool, Sqlite can be used in many different ways according to the needs of the application. Therefore you should be aware that such an operation may take relatively longer to complete than another operation that doesn't access the local file system. Creating a database connection for example essentially accesses the files stored locally on the device. So you need to consider these constraints when designing your database. Your database definition can contain tables and indexes.Īs with all database engines, you are effectively accessing the file system each time you access a table or index. ![]() Once you have defined the structure of your database, it is automatically managed for you by Android. Sqlite is integrated into all Android devices and therefore a Sqlite database does not require any configuration or setting up. It provides support for standard relational database features such as prepared statements and transactions, as well as providing SQL syntax. It is serverless, self-contained and requires zero configuration. In summary though, Sqlite is an open source and widely used database management engine with a very small footprint that makes it ideal for use in mobile applications. If you haven't already heard of Sqlite, then I suggest you read up on it before going any further. BackgroundĪndroid comes with built-in integration with the database Sqlite. It is up to the developer to decide exactly what data they want to store locally, and how often they update that data. Data that is retrieved from local storage will be quicker than remote data retrieved via web services and is not at the mercy of connectivity problems if you are in a bad signal area. Unless your data is highly volatile, then storing the data on the device in a database makes sense. Although your application may initially receive its data via a web service, you may want to store the data on the device so that you do not need to keep requesting it from your web services. If you have ever developed an Android application using the Xamarin plug-in for Visual Studio, then chances are that you will have had a requirement to store and retrieve data.
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