Delete

Delete

The delete method is available in both AsyncDbEngine and DbEngine and is used to delete documents from a MongoDB collection based on a specified query. This method offers a straightforward way to remove documents that match specific criteria from your MongoDB database.

AsyncSync

from pyodmongo import AsyncDbEngine, DbModel, DbResponse
from typing import ClassVar
import asyncio

engine = AsyncDbEngine(mongo_uri="mongodb://localhost:27017", db_name="my_db")


class Product(DbModel):
    name: str
    price: float
    is_available: bool
    _collection: ClassVar = "products"


async def main():
    query = Product.price <= 100

    response: DbResponse = await engine.delete(Model=Product, query=query)


asyncio.run(main())

from pyodmongo import DbEngine, DbModel, DbResponse
from typing import ClassVar

engine = DbEngine(mongo_uri="mongodb://localhost:27017", db_name="my_db")


class Product(DbModel):
    name: str
    price: float
    is_available: bool
    _collection: ClassVar = "products"


query = Product.price <= 100

response: DbResponse = engine.delete(Model=Product, query=query)

Arguments

• Model: DbModel: The class that inherits from DbModel and serves as the base for querying the database.
• query: ComparisonOperator | LogicalOperator: A query that defines the criteria for selecting the documents to be deleted.
• raw_query: dict (optional): A raw query in dictionary format accepted by MongoDB.

Warning

Under the hood, the delete method uses MongoDB's delete_many operation to remove documents. All documents that match the query criteria will be deleted from the collection.

Delete one

In PyODMongo, there is only the delete method. To ensure that only one document is deleted, you can pass the attribute delete_one=True to the delete method. This way, only the first document that matches the specified query will be deleted.

AsyncSync

from pyodmongo import AsyncDbEngine, DbModel, DbResponse
from typing import ClassVar
import asyncio

engine = AsyncDbEngine(mongo_uri="mongodb://localhost:27017", db_name="my_db")


class Product(DbModel):
    name: str
    price: float
    is_available: bool
    _collection: ClassVar = "products"


async def main():
    query = Product.name == "Box"

    response: DbResponse = await engine.delete(
        Model=Product, query=query, delete_one=True
    )


asyncio.run(main())

from pyodmongo import DbEngine, DbModel, DbResponse
from typing import ClassVar

engine = DbEngine(mongo_uri="mongodb://localhost:27017", db_name="my_db")


class Product(DbModel):
    name: str
    price: float
    is_available: bool
    _collection: ClassVar = "products"


query = Product.name == "Box"

response: DbResponse = engine.delete(Model=Product, query=query, delete_one=True)

Delete Response

The delete method in PyODMongo returns a DbResponse object that provides information about the outcome of the delete operation. This object contains several attributes that give insights into how the delete operation affected the database.

Atributos de DbResponse

• acknowledged: bool: A boolean value indicating whether the operation was acknowledged by the MongoDB server. If the operation was acknowledged, this attribute is set to True, indicating that the server recognized and processed the save request.

• deleted_count: int: An integer representing the number of documents that were deleted from the database as part of the delete operation.

• inserted_count: int: An integer that indicates the number of documents that were successfully inserted into the database during the insert operation.

• matched_count: int: An integer that represents the number of documents in the database that matched the query or criteria specified during the save operation. This count indicates how many existing documents were updated as part of the save operation.

• modified_count: int: An integer that represents the number of documents in the database that were actually modified during the save operation. This count is usually the same as or a subset of the matched_count and indicates how many documents had their fields changed.

• upserted_count: int: An integer that represents the number of documents that were inserted as a result of an upsert operation. This occurs when a document does not exist and is created during the update process.

• upserted_ids: dict[int, Id]: A dictionary that maps the index of the upserted documents to their new unique IDs. This attribute is useful for tracking which documents were created during an upsert operation.