Document Source Code Reverse Relation Add Child Raise Error

[fourcels]

Describe the bug

https://collerek.github.io/ormar/relations/foreign-key/#add

department = await Department(name="Science").save()
course = Course(name="Math", completed=False) # note - not saved

await department.courses.add(course)
assert course.pk is not None # child model was saved
# relation on child model is set and FK column saved in db
assert courses.department == department
# relation on parent model is also set
assert department.courses[0] == course 

To Reproduce

from typing import Optional

import databases
import sqlalchemy
import asyncio

import ormar

DATABASE_URL = "sqlite:///db.sqlite"
database = databases.Database(DATABASE_URL)
metadata = sqlalchemy.MetaData()
# get your database url in sqlalchemy format - same as used with databases instance used in Model definition
engine = sqlalchemy.create_engine(DATABASE_URL)
# note that this has to be the same metadata that is used in ormar Models definition


class Department(ormar.Model):
    class Meta:
        database = database
        metadata = metadata

    id: int = ormar.Integer(primary_key=True)
    name: str = ormar.String(max_length=100)


class Course(ormar.Model):
    class Meta:
        database = database
        metadata = metadata

    id: int = ormar.Integer(primary_key=True)
    name: str = ormar.String(max_length=100)
    completed: bool = ormar.Boolean(default=False)
    department: Optional[Department] = ormar.ForeignKey(Department)


async def run():
    await database.connect()
    department = await Department(name="Science").save()
    course = Course(name="Math", completed=False)  # note - not saved

    await department.courses.add(course)
    await database.disconnect()

if __name__ == "__main__":
    metadata.create_all(engine)
    asyncio.run(run())

Error: ormar.exceptions.ModelPersistenceError: You cannot update not saved model! Use save or upsert method.

(Note: this should be a complete and concise piece of code that allows reproduction of an issue)

Expected behavior
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Screenshots
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Versions (please complete the following information):

• Database backend used (mysql/sqlite/postgress)
• Python 3.9.5
• ormar 0.10.9
• pydantic version

Additional context
Add any other context about the problem here.

[collerek]

Thanks for catching that - fixed in 0.10.10