Get Document

Database

We will start with the same database structure and the same amount of data as previously.

Get First Document

Sometimes we need to get one object. In that scenario, we will use the classmethod get.

The get is a classmethod that returns a single object.

The method will raise an error if no document exists.

The exception type will be ObjectDoesNotExist, inherited from Python's Exception. Import ObjectDoesNotExist from mongodb_odm.exceptions.

# Code omitted above

def get_document():
    try:
        player = Player.get(filter={Player.country_code: "example@test.com"})
        print(player)
    except ObjectDoesNotExist as ex:
        print(ex)

# Code omitted below

Full file preview

import os
from typing import Optional

from mongodb_odm import (
    ASCENDING,
    DESCENDING,
    Document,
    IndexModel,
    apply_indexes,
    connect,
)
from mongodb_odm.exceptions import ObjectDoesNotExist


class Player(Document):
    name: str
    country_code: str
    rating: Optional[int] = None

    class ODMConfig(Document.ODMConfig):
        indexes = [
            IndexModel([("rating", ASCENDING)]),
        ]


def configuration():
    connect(os.environ.get("MONGO_URL", "mongodb://localhost:27017/testdb"))
    apply_indexes()


def create_players():
    Player(name="Pelé", country_code="BRA", rating=98).create()
    Player(name="Diego Maradona", country_code="ARG", rating=97).create()
    Player(name="Zinedine Zidane", country_code="FRA", rating=94).create()
    Player(name="Ronaldo", country_code="BRA", rating=94).create()
    Player(name="Neymar", country_code="BRA", rating=89).create()
    Player(name="Lionel Messi", country_code="ARG", rating=91).create()
    Player(name="Ángel Di María", country_code="ARG", rating=84).create()
    Player(name="Karim Benzema", country_code="FRA", rating=89).create()
    Player(name="Antoine Griezmann", country_code="FRA", rating=85).create()
    Player(name="Kylian Mbappé", country_code="FRA", rating=91).create()
    Player(name="Gerd Müller", country_code="GER").create()
    Player(name="Miroslav Klose", country_code="GER", rating=91).create()
    Player(name="Thomas Müller", country_code="GER", rating=87).create()
    Player(name="Cristiano Ronaldo", country_code="POR", rating=87).create()
    Player(name="Eusébio", country_code="POR", rating=93).create()
    Player(name="Diogo Jota", country_code="POR", rating=85).create()
    Player(name="David Beckham", country_code="ENG", rating=89).create()
    Player(name="Wayne Rooney", country_code="ENG", rating=80).create()
    Player(name="Harry Kane", country_code="ENG", rating=89).create()


def get_document():
    try:
        player = Player.get(filter={Player.country_code: "example@test.com"})
        print(player)
    except ObjectDoesNotExist as ex:
        print(ex)


def get_last_document():
    player = Player.get(
        filter={Player.rating: {"$gte": 90}}, sort=[("_id", DESCENDING)]
    )
    print(player)


def main():
    configuration()

    get_document()
    create_players()

    get_document()
    get_last_document()


if __name__ == "__main__":
    main()

If the filter matches the collection data, then it will return a Player type object.

Get Last Document

To find the last document from the collection we also use find_last.

# Code omitted above

def get_last_document():
    player = Player.get(
        filter={Player.rating: {"$gte": 90}}, sort=[("_id", DESCENDING)]
    )

# Code omitted below

Full file preview

import os
from typing import Optional

from mongodb_odm import (
    ASCENDING,
    DESCENDING,
    Document,
    IndexModel,
    apply_indexes,
    connect,
)
from mongodb_odm.exceptions import ObjectDoesNotExist


class Player(Document):
    name: str
    country_code: str
    rating: Optional[int] = None

    class ODMConfig(Document.ODMConfig):
        indexes = [
            IndexModel([("rating", ASCENDING)]),
        ]


def configuration():
    connect(os.environ.get("MONGO_URL", "mongodb://localhost:27017/testdb"))
    apply_indexes()


def create_players():
    Player(name="Pelé", country_code="BRA", rating=98).create()
    Player(name="Diego Maradona", country_code="ARG", rating=97).create()
    Player(name="Zinedine Zidane", country_code="FRA", rating=94).create()
    Player(name="Ronaldo", country_code="BRA", rating=94).create()
    Player(name="Neymar", country_code="BRA", rating=89).create()
    Player(name="Lionel Messi", country_code="ARG", rating=91).create()
    Player(name="Ángel Di María", country_code="ARG", rating=84).create()
    Player(name="Karim Benzema", country_code="FRA", rating=89).create()
    Player(name="Antoine Griezmann", country_code="FRA", rating=85).create()
    Player(name="Kylian Mbappé", country_code="FRA", rating=91).create()
    Player(name="Gerd Müller", country_code="GER").create()
    Player(name="Miroslav Klose", country_code="GER", rating=91).create()
    Player(name="Thomas Müller", country_code="GER", rating=87).create()
    Player(name="Cristiano Ronaldo", country_code="POR", rating=87).create()
    Player(name="Eusébio", country_code="POR", rating=93).create()
    Player(name="Diogo Jota", country_code="POR", rating=85).create()
    Player(name="David Beckham", country_code="ENG", rating=89).create()
    Player(name="Wayne Rooney", country_code="ENG", rating=80).create()
    Player(name="Harry Kane", country_code="ENG", rating=89).create()


def get_document():
    try:
        player = Player.get(filter={Player.country_code: "example@test.com"})
        print(player)
    except ObjectDoesNotExist as ex:
        print(ex)


def get_last_document():
    player = Player.get(
        filter={Player.rating: {"$gte": 90}}, sort=[("_id", DESCENDING)]
    )
    print(player)


def main():
    configuration()

    get_document()
    create_players()

    get_document()
    get_last_document()


if __name__ == "__main__":
    main()

The get method accepts the sort kwargs argument. The sort kwargs accepts several types of data.

The data type is Union[str, Sequence[tuple[str, Union[int, str, Mapping[str, Any]]]]].