用orm的model来操作one-to-many关联，新建是能新建，update时各种问题，最后还是得手动处理many侧的增删。
看issue，相关issue提了几年都没人修，20k star的项目有2k的issue。
Unable to delete subordinate relation entity when saving parent entity #3938
Using .save for one-to-many relationship always tries to insert instead of update. #3095
就这？还不如用sequelize
看issue，相关issue提了几年都没人修，20k star的项目有2k的issue。
Unable to delete subordinate relation entity when saving parent entity #3938
Using .save for one-to-many relationship always tries to insert instead of update. #3095
就这？还不如用sequelize
