allprojects {

repositories {

jcenter()

maven { url 'https://maven.google.com' }

}

}

implementation "android.arch.persistence.room:runtime:1.0.0-beta2"
annotationProcessor "android.arch.persistence.room:compiler:1.0.0-beta2"

implementation "android.arch.persistence.room:rxjava2:1.0.0-beta2"

User.java
@Entity(tableName = "users")
public class User {
    private static final String DEFAULT_PW = "12345678";
    @NonNull
    @PrimaryKey(autoGenerate = true)
    @ColumnInfo(name = "id")
    private int mId;
    @ColumnInfo(name = "first_name")
    private String mFirstName;
    @ColumnInfo(name = "last_name")
    private String mLastName;
    @ColumnInfo(name = "password")
    private String mPassword;
    @Embedded
    private Place mPlace;

    public User() {
    }

    @Ignore
    public User(String firstName, String lastName) {
        mFirstName = firstName;
        mLastName = lastName;
        mPassword = DEFAULT_PW;
    }

    @Override
    public String toString() {
        if (mPlace != null) {
            return mFirstName + " " + mLastName + "\n" + mPlace.getName();
        }
        return mFirstName + " " + mLastName;
    }
}

Place.java
@Entity(tableName = "place")
public class Place {
    @PrimaryKey(autoGenerate = true)
    private int mId;
    @ColumnInfo(name = "lat")
    private double mLat;
    @ColumnInfo(name = "lng")
    private double mLng;
    @ColumnInfo(name = "name")
    private String mName;

    public Place() {
    }
}

@PrimaryKey(autoGenerate = true)
private int mId;

@Entity(indices = {@Index(value = {"first_name", "last_name"}})

@Entity(indices = {@Index(value = {"first_name", "last_name"},
       unique = true)}

@Embedded
    private Place mPlace;

@Entity(foreignKeys = @ForeignKey(entity = User.class,
                                  parentColumns = "id",
                                  childColumns = "user_id"))
class Pet {
    @PrimaryKey
    public int petId;

    public String name;

    @ColumnInfo(name = "user_id")
    public int userId;
}

@Dao
public interface UserDAO {
    @Query("SELECT * FROM users WHERE id = :userId")
    Flowable<User> getUserByUserId(int userId);

    @Query("SELECT * FROM users WHERE first_name LIKE :userName OR last_name LIKE :userName")
    Flowable<List<User>> getUserByName(String userName);

    @Query("SELECT * FROM users")
    Flowable<List<User>> getALlUser();

    @Insert
    void insertUser(User... users);

    @Delete
    void deleteUser(User user);

    @Query("DELETE FROM users")
    void deleteAllUser();

    @Update
    void updateUser(User... users);
}

@Database(entities = {User.class}, version = DATABASE_VERSION)
public abstract class UserDatabase extends RoomDatabase{
    private static UserDatabase sUserDatabase;

    public static final int DATABASE_VERSION = 2;
    public static final String DATABASE_NAME = "Room-database";

    public abstract UserDAO userDAO();

    public static UserDatabase getInstance(Context context) {
        if (sUserDatabase == null) {
            sUserDatabase = Room.databaseBuilder(context, UserDatabase.class, DATABASE_NAME)
                .fallbackToDestructiveMigration()
                .build();
        }
        return sUserDatabase;
    }
}