Flutter利用ORM框架管理数据库详解

@Database(version: 1, entities: [Memo])

Migration(this.startVersion, this.endVersion, this.migrate)

final database = await $FloorAppDatabase
    .databaseBuilder('app_database.db')
    .addMigrations([migration1to3, migration2to3])
    .build();

@Database(version: 2, entities: [Memo])

@entity
class Memo {
  @PrimaryKey(autoGenerate: true)
  final int? id;
  String title;
  String content;
  @ColumnInfo(name: 'created_time')
  DateTime createdTime;
  @ColumnInfo(name: 'modified_time')
  DateTime modifiedTime;
  String? category;
  List<String> tags;

  Memo({
    this.id,
    required this.title,
    required this.content,
    required this.createdTime,
    required this.modifiedTime,
    this.category = '',
    required this.tags,
  });
}

final migration1to2 = Migration(1, 2, (database) async {
  await database.execute('ALTER TABLE Memo ADD COLUMN category TEXT');
  // 可选，设置旧版本字段初始值
  await database.update('Memo',{'category': ''});
});

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();

  final database = await $FloorMemoDatabase
      .databaseBuilder('app_database.db')
      .addMigrations([migration1to2]).build();

  final dao = database.memoDao;

  getIt.reGISterSingleton<MemoDao>(dao, signalsReady: true);

  runApp(const MyApp());
}

flutter packages pub run build_runner build