What types of data storage exist in Android applications?

The following data storage types are available in Android applications:

• Shared Preferences: For storing small sets of primitive data (key-value). Suitable for user settings.

• Internal Storage: For storing files on the device's internal memory. Accessible only to the app that created the file. Deleted when the app is uninstalled.

• External Storage: For storing files on the device's external memory (SD card or internal partition accessible via MTP). May be accessible to other apps and the user. Permissions are required.

• SQLite Databases: For storing structured data in a relational database. Ideal for large volumes of data requiring complex queries.

  -- Example of creating a table
  CREATE TABLE users (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      name TEXT,
      age INTEGER
  );
  

• DataStore: A more modern alternative to Shared Preferences. Allows storing typed data asynchronously. Supports Flow.

  // Example of using Preference DataStore
  val Context.dataStore: DataStore<Preferences> by preferencesDataStore(name = "settings")
  

• Room Persistence Library: An abstraction over SQLite. Simplifies database operations, provides a safer way to access data, and supports LiveData and Flow.

  // Example DAO with Room
  @Dao
  interface UserDao {
      @Query("SELECT * FROM user")
      fun getAll(): List<User>
  
      @Insert
      fun insertAll(vararg users: User)
  }