如何通过android房间将数据库设置的新值更新为旧值？

dependencies {
    implementation "androidx.room:room-runtime:2.4.0"
    annotationProcessor "androidx.room:room-compiler:2.4.0"
}

@Entity(tableName = "users")
public class User {
    @PrimaryKey
    public int id;
    
    public String name;
    public int age;
    
    // 构造函数、Getter 和 Setter 方法等
}

@Dao
public interface UserDao {
    @Insert
    void insertUser(User user);
    
    @Update
    void updateUser(User user);
    
    // 其他查询和删除方法等
}

@Database(entities = {User.class}, version = 1)
public abstract class AppDatabase extends RoomDatabase {
    public abstract UserDao userDao();
}

// 初始化数据库
AppDatabase db = Room.databaseBuilder(getApplicationContext(),
        AppDatabase.class, "my-database").build();

// 插入新用户
User newUser = new User();
newUser.id = 1;
newUser.name = "John";
newUser.age = 25;
db.userDao().insertUser(newUser);

// 更新用户信息
User existingUser = db.userDao().getUserById(1);
existingUser.name = "John Doe";
existingUser.age = 26;
db.userDao().updateUser(existingUser);