TigerBetree / RoomGreenDaoDemo

Room GreenDao 学习

Room

• 参考文档

• 依赖

  // model build.gradle
  
  // Room dependencies
  implementation "android.arch.persistence.room:runtime:1.0.0"
  annotationProcessor "android.arch.persistence.room:compiler:1.0.0"
  
  defaultConfig {
      ...
  
      // Room Schema
      javaCompileOptions {
          annotationProcessorOptions {
              arguments = ["room.schemaLocation":
                                       "$projectDir/schemas".toString()]
          }
      }
  }
  

• demo

  @Entity(tableName = "User")
  public class User {
  
      @PrimaryKey(autoGenerate = true) // 自增
      public int uid;
  
      @ColumnInfo(name = "userName")
      public String name;
  
      public int age;
  }
  
  @Dao
  public interface UserDao {
  
      @Query("select * from user")
      List<User> getAllUsers();
  
      @Insert
      void insertUsers(User... users);
  
      @Delete
      void deleteUser(User user);
  }
  
  @Database(version = 1, entities = {User.class})
  public abstract class AppDataBase extends RoomDatabase {
  
      public abstract UserDao userDao();
  
      public static AppDataBase getDB() {
          return Room.databaseBuilder(MyApp.getInstance(), AppDataBase.class, "mRoomDB")
                  // 版本升级
                  // .addMigrations(MIGRATION_1_2, MIGRATION_2_3)
  
                  // Room不允许在主线程中访问数据库，除非在buid的时候使用allowMainThreadQueries()方法
                  // .allowMainThreadQueries()
                  .build();
      }
  
  //    static final Migration MIGRATION_1_2 = new Migration(1, 2) {
  //        @Override
  //        public void migrate(SupportSQLiteDatabase database) {
  //            database.execSQL("CREATE TABLE `Fruit` (`id` INTEGER, "
  //                    + "`name` TEXT, PRIMARY KEY(`id`))");
  //        }
  //    };
  //
  //    static final Migration MIGRATION_2_3 = new Migration(2, 3) {
  //        @Override
  //        public void migrate(SupportSQLiteDatabase database) {
  //            database.execSQL("ALTER TABLE Book "
  //                    + " ADD COLUMN pub_year INTEGER");
  //        }
  //    };
  }
  
  

GreenDao

• Github