在FASTAPI上使用PyMongo将元素插入到嵌套模型Mongodb数组中

Question

最近，我继续将元素插入到由父文档持有的数组中。基本上，我的模型代表了一列可以有很多货车的火车。马车是一个载着马车的数组。

这是我的数据库模型

rom typing import Optional,Union

from pydantic import BaseModel, EmailStr, Field

#Wagon Model
class Wagon(BaseModel):
    no: int = Field(...)
    wagon_code: str = Field(...)
    wagon_type: str = Field(...)
    passengers_on_board: int = Field(...)
    max_capacity: int = Field(...)
    weight: float = Field(...)
    dimension: tuple  = Field(...)

    class Config:
        schema_extra = {
            "example": {
                "no": 3,
                "wagon_code": "GA151-03",
                "wagon_type": "Penumpang",
                "passengers_on_board": 40,
                "max_capacity":80,
                "weight":1050.01,
                "dimension": (20.62,9.91,4.15)
            }
        }

class UpdateWagon(BaseModel):
    no: Optional[int] 
    wagon_code: Optional[str]
    wagon_type: Optional[str]
    passengers_on_board: Optional[int]
    max_capacity: Optional[int]
    weight: Optional[float]
    dimension: Optional[tuple]
    
    class Config:
        schema_extra = {
            "example": {
                "no": 3,
                "wagon_code": "GA151-03",
                "wagon_type": "Penumpang",
                "passengers_on_board": 64,
                "max_capacity":80,
                "weight":1050.01,
                "dimension": (20.62,9.91,4.15)
            }
        }


#Train Model
class Train(BaseModel):
    name: str = Field(...)
    no: str = Field(...)
    first_station: str = Field(...)
    last_station: str = Field(...)
    from_: str = Field(...)
    to_: str = Field(...)
    current_station: str = Field(...)
    position: Optional[tuple]
    wagons: Union[list[Wagon], None] = None

    class Config:
        schema_extra = {
            "example": {
                "name": "Gajayana",
                "no": "GA-151",
                "first_station": "Malang - Kota Baru",
                "last_station": "Jakarta - Gambir",
                "from_":"Malang - Kota Baru",
                "to_":"Malang - Kota Lama",
                "current_station":"Malang - Kota Baru",
                "position": (2.12,2.12),
                "wagons" : [],
                }
        }

class UpdateTrain(BaseModel):
    name: Optional[str]
    no: Optional[str]
    first_station: Optional[str]
    last_station: Optional[str]
    from_: Optional[str]
    to_: Optional[str]
    current_station: Optional[str]
    position: Optional[tuple]
    wagons: Optional[list]

    class Config:
        schema_extra = {
            "example": {
                "name": "Gajayana",
                "no": "GA-151",
                "first_station": "Malang - Kota Baru",
                "last_station": "Jakarta - Gambir",
                "from_":"Malang - Kota Lama",
                "to_":"Kepanjen",
                "current_station":"Malang - Kota Baru",
                "position": (2.08,2.16),
                "wagons": [],
            }
        }

我用arrayFilters把新造的马车附加到火车上。然而，我没有运气附加模型，但一个新的旅行车创建了如下所示的功能。

async def add_wagon(train_no: str,wagon_data: dict) -> dict:
    wagon = await wagon_collection.insert_one(wagon_data)
    new_wagon = await wagon_collection.find_one({"_id": wagon.inserted_id})
    train = await train_collection.find_one({"no": train_no})
    if train:
        train_collection.update_one({"no": train_no},{"$set":{"wagons.$[element]":new_wagon}},array_filters=[{"element":{"$exists":"false"}}],upsert=True)
    return wagon_helper(new_wagon)

该模型被用作FASTAPI的API。上面的操作是使用PUT方法完成的，路由如下所示。

@router.put("{train_no}/wagons/", response_description="Wagon data added into the database")
async def add_wagon_data(train_no: str,wagon: Wagon = Body(...)):
    wagon = jsonable_encoder(wagon)
    new_wagon = await add_wagon(train_no,wagon)
    return ResponseModel(new_wagon, "Wagon added successfully")

我的arrayFilters是错的吗？还是我使用$exists作为完全相等匹配的方式是不正确的？

Answer 1

原来我想得太复杂了。USing $push和upsert=True一起解决了这个问题。

async def add_wagon(train_no: str,wagon_data: dict) -> dict:
    wagon = await wagon_collection.insert_one(wagon_data)
    new_wagon = await wagon_collection.find_one({"_id": wagon.inserted_id})
    train = await train_collection.find_one({"no": train_no})
    if train:
        train_collection.update_one({"no": train_no},{"$push":{"wagons":new_wagon}},upsert=True)
    return wagon_helper(new_wagon)