[안드로이드 Room] 시작하기

설정

ㆍ종속성 설정

dependencies {
    implementation "androidx.room:room-runtime:2.1.0-alpha07"
    annotationProcessor "androidx.room:room-compiler:2.1.0-alpha07" // For Kotlin use kapt instead of annotationProcessor
}

구성요소

User.java

ㆍEntity 생성

@Entity
public class User {
    @PrimaryKey
    public int uid;
 
    @ColumnInfo(name = "first_name")
    public String firstName;
 
    @ColumnInfo(name = "last_name")
    public String lastName;
}

UserDao.java

ㆍDao 생성

@Dao
public interface UserDao {
    @Query("SELECT * FROM user")
    List<User> getAll();
 
    @Query("SELECT * FROM user WHERE uid IN (:userIds)")
    List<User> loadAllByIds(int[] userIds);
 
    @Query("SELECT * FROM user WHERE first_name LIKE :first AND " +
           "last_name LIKE :last LIMIT 1")
    User findByName(String first, String last);
 
    @Insert
    void insertAll(User... users);
 
    @Delete
    void delete(User user);
}

AppDatabase.java

ㆍRoomDatabase 생성

@Database(entities = {User.class}, version = 1)
public abstract class AppDatabase extends RoomDatabase {
    public abstract UserDao userDao();
 
    private static AppDatabase INSTANCE;
 
    static final Migration MIGRATION_1_2 = new Migration(1, 2) {
        @Override
        public void migrate(SupportSQLiteDatabase database) {
            // Since we didn't alter the table, there's nothing else to do here.
        }
    };
 
    public static AppDatabase getInstance(Context context) {
        if (INSTANCE == null) {
            INSTANCE = buildDatabase(context);
        }
        return INSTANCE;
    }
 
    private static AppDatabase buildDatabase(Context context) {
        return Room.databaseBuilder(context,
                AppDatabase.class, "database-name.db")
                .addMigrations(MIGRATION_1_2)
                .build();
    }
}

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출처

https://developer.android.com/training/data-storage/room/index.html