Tag: PrimaryKey

Defines our SQLite database tables. This example corresponds to the @DAO and Build A Database entries.

Create a custom class to define your table, using Entity to annotate it
@Entity(tableName = "contacts") // Name of table specified as 'contacts'. It is common for database tables and their corresponding classes to not have same name
public class ContactEntry {

    @PrimaryKey(autoGenerate = true) // States that the next variable will be the table's primary key (and therefore unique)
    private int id; // Each member variable corresponds to a column in the table
    private String name; // Each member variable corresponds to a column in the table
    @ColumnInfo(name = "contactAge") // If you wish to specifically state the name of the column use this annotation
    private int age; // Each member variable corresponds to a column in the table

    @Ignore // If you do not want a variable to appear in the table use the @ignore annotation
    private String address;

    @Ignore // Tell Room to use the other constructor (which includes the id field) using the @Ignore annotation, as Room can only use one constructor. This constructor will be used when the user adds a new entry, as they will not know the id of the new entry.
    public ContactEntry (String name, int age) {
        this.description = name;
        this.age = age;
    }

    public ContactEntry (int id, String name, int age) {
        this.id = id;
        this.description = name;
        this.age = age;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name= name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }
}

To create the table you will need to Build A Database. To interact with the table you will need to create a @DAO.