Sequelize – 使用关联表进行search，但排除关联表的结果

是否可以使用关联表进行search，但不包括关联表中的数据？

例如

db.Bill.findAll({ include: [{ model: self.db.Group, where: { id: groupId }, include: [{ model: self.db.Account, where: {username: username} }] }] }); 

目前，我得到这些结果…

 [ { "id": 2, "title": "Title", "category": "OTHERS", "currency": "php", "recurring": false, "date_from": null, "date_to": null, "createdAt": "2015-08-12T10:54:08.000Z", "updatedAt": "2015-08-12T10:54:08.000Z", "group_id": 2, "Group": { "id": 2, "name": "Group", "createdAt": "2015-08-12T10:54:07.000Z", "updatedAt": "2015-08-12T10:54:07.000Z", "Account": { "username": "username" } } } ] 

我想找一个小组下的所有账单，但我只想要结果

 [ { "id": 2, "title": "Title", "category": "OTHERS", "currency": "php", "recurring": false, "date_from": null, "date_to": null, "createdAt": "2015-08-12T10:54:08.000Z", "updatedAt": "2015-08-12T10:54:08.000Z", "group_id": 2 } ];