10. Query Writes
Update and delete a selection using Query conditions, ordering, and limits. Both operations return the number of affected records.
Source
"""Update and delete a selection using Query conditions, ordering, and limits.
Both operations return the number of affected records.
"""
import asyncio
from uuid import UUID, uuid4
from common import backend, database
from sqlmodel import Field as SQLField
from fastsprout.actions import DataS
from fastsprout.core import Field, ReadField
from fastsprout.data import DataR, sql
class Hero(sql.SQLEntity[UUID]):
__signpost__ = backend
id: ReadField[UUID] = SQLField(default_factory=uuid4, primary_key=True)
name: Field[str]
power: Field[int]
heroes = DataS(Hero)
async def main() -> None:
async with database():
async with DataR() as datar:
await heroes.bulk_create(
(
Hero(name=name, power=power)
for name, power in (("Batman", 80), ("Robin", 50))
),
datar=datar,
).to_list()
query = datar.ability(Hero).query_for(Hero)
selection = query.copy().where(Hero.name.eq("Robin"))
updated = await heroes.update_by_query(
selection, Hero.power.set(60), datar=datar
)
print("Updated:", updated)
async for hero in heroes.stream(
query.order_by(Hero.power), datar=datar
):
print(hero.name, hero.power)
deleted = await heroes.delete_by_query(
query.copy().limit(1), datar=datar
)
print("Deleted:", deleted)
print("Remaining:", await heroes.count(datar=datar))
if __name__ == "__main__":
asyncio.run(main())