abstract class DataBase { static late DataBase _dataBase; static DataBase getInstance() { return _dataBase; } static void setInstance(DataBase database) { _dataBase = database; } bool isConnected(); // 执行查询操作 Future>> query(String table, {dynamic condition}); // 执行插入操作 Future insert(String table, Map data); // 执行更新操作 Future update( String table, Map data, dynamic condition, {bool multiUpdate = false}); // 执行删除操作 Future delete(String table, dynamic condition); //查询数量 Future count(String tbale, {dynamic condition}); } enum DataBaseType { mongo, sqlite } class DataBaseConfig { DataBaseType type; String host; String userName; String password; String dataBase; DataBaseConfig({ this.type = DataBaseType.mongo, this.host = '', this.userName = '', this.password = '', required this.dataBase, }); }