FastAPIにおけるリレーションシップを持つモデル¶
今すぐIDで単一のヒーローを読み込むと、チームID付きのヒーローデータが取得できます。
しかし、特定のチームに関するデータは何も取得できません

次のレスポンスが取得されます
{
"name": "Deadpond",
"secret_name": "Dive Wilson",
"age": null,
"team_id": 1,
"id": 1,
}
同様に、IDでチームを取得すると、チームデータは取得できますが、このチームのヒーローに関する情報は何も取得できません。

ここでは、次のレスポンスが取得されます
{
"name": "Preventers",
"headquarters": "Sharp Tower",
"id": 2
}
...しかし、ヒーローに関する情報はありません。
それを更新しましょう。🤓
なぜもっと多くのデータが取得できないのか¶
まず、なぜ各ヒーローと各チームの関連データが取得できないのでしょうか?
それは、HeroPublicをHeroBaseの同じ基本フィールドに加えてidのみで宣言したからです。しかし、リレーションシップ属性用のフィールドteamは含まれていません。
同様に、TeamPublicをTeamBaseの同じ基本フィールドに加えてidのみで宣言しました。しかし、リレーションシップ属性用のフィールドheroesは含まれていません。
# Code above omitted 👆
class TeamBase(SQLModel):
name: str = Field(index=True)
headquarters: str
# Code here omitted 👈
class TeamPublic(TeamBase):
id: int
# Code here omitted 👈
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: int | None = Field(default=None, index=True)
team_id: int | None = Field(default=None, foreign_key="team.id")
# Code here omitted 👈
class HeroPublic(HeroBase):
id: int
# Code below omitted 👇
# Code above omitted 👆
class TeamBase(SQLModel):
name: str = Field(index=True)
headquarters: str
# Code here omitted 👈
class TeamPublic(TeamBase):
id: int
# Code here omitted 👈
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: Optional[int] = Field(default=None, index=True)
team_id: Optional[int] = Field(default=None, foreign_key="team.id")
# Code here omitted 👈
class HeroPublic(HeroBase):
id: int
# Code below omitted 👇
# Code above omitted 👆
class TeamBase(SQLModel):
name: str = Field(index=True)
headquarters: str
# Code here omitted 👈
class TeamPublic(TeamBase):
id: int
# Code here omitted 👈
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: Optional[int] = Field(default=None, index=True)
team_id: Optional[int] = Field(default=None, foreign_key="team.id")
# Code here omitted 👈
class HeroPublic(HeroBase):
id: int
# Code below omitted 👇
👀 ファイルの完全なプレビュー
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Relationship, Session, SQLModel, create_engine, select
class TeamBase(SQLModel):
name: str = Field(index=True)
headquarters: str
class Team(TeamBase, table=True):
id: int | None = Field(default=None, primary_key=True)
heroes: list["Hero"] = Relationship(back_populates="team")
class TeamCreate(TeamBase):
pass
class TeamPublic(TeamBase):
id: int
class TeamUpdate(SQLModel):
name: str | None = None
headquarters: str | None = None
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: int | None = Field(default=None, index=True)
team_id: int | None = Field(default=None, foreign_key="team.id")
class Hero(HeroBase, table=True):
id: int | None = Field(default=None, primary_key=True)
team: Team | None = Relationship(back_populates="heroes")
class HeroPublic(HeroBase):
id: int
class HeroCreate(HeroBase):
pass
class HeroUpdate(SQLModel):
name: str | None = None
secret_name: str | None = None
age: int | None = None
team_id: int | None = None
sqlite_file_name = "database.db"
sqlite_url = f"sqlite:///{sqlite_file_name}"
connect_args = {"check_same_thread": False}
engine = create_engine(sqlite_url, echo=True, connect_args=connect_args)
def create_db_and_tables():
SQLModel.metadata.create_all(engine)
def get_session():
with Session(engine) as session:
yield session
app = FastAPI()
@app.on_event("startup")
def on_startup():
create_db_and_tables()
@app.post("/heroes/", response_model=HeroPublic)
def create_hero(*, session: Session = Depends(get_session), hero: HeroCreate):
db_hero = Hero.model_validate(hero)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
@app.get("/heroes/", response_model=list[HeroPublic])
def read_heroes(
*,
session: Session = Depends(get_session),
offset: int = 0,
limit: int = Query(default=100, le=100),
):
heroes = session.exec(select(Hero).offset(offset).limit(limit)).all()
return heroes
@app.get("/heroes/{hero_id}", response_model=HeroPublic)
def read_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
return hero
@app.patch("/heroes/{hero_id}", response_model=HeroPublic)
def update_hero(
*, session: Session = Depends(get_session), hero_id: int, hero: HeroUpdate
):
db_hero = session.get(Hero, hero_id)
if not db_hero:
raise HTTPException(status_code=404, detail="Hero not found")
hero_data = hero.model_dump(exclude_unset=True)
for key, value in hero_data.items():
setattr(db_hero, key, value)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
@app.delete("/heroes/{hero_id}")
def delete_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
session.delete(hero)
session.commit()
return {"ok": True}
@app.post("/teams/", response_model=TeamPublic)
def create_team(*, session: Session = Depends(get_session), team: TeamCreate):
db_team = Team.model_validate(team)
session.add(db_team)
session.commit()
session.refresh(db_team)
return db_team
@app.get("/teams/", response_model=list[TeamPublic])
def read_teams(
*,
session: Session = Depends(get_session),
offset: int = 0,
limit: int = Query(default=100, le=100),
):
teams = session.exec(select(Team).offset(offset).limit(limit)).all()
return teams
@app.get("/teams/{team_id}", response_model=TeamPublic)
def read_team(*, team_id: int, session: Session = Depends(get_session)):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
return team
@app.patch("/teams/{team_id}", response_model=TeamPublic)
def update_team(
*,
session: Session = Depends(get_session),
team_id: int,
team: TeamUpdate,
):
db_team = session.get(Team, team_id)
if not db_team:
raise HTTPException(status_code=404, detail="Team not found")
team_data = team.model_dump(exclude_unset=True)
for key, value in team_data.items():
setattr(db_team, key, value)
session.add(db_team)
session.commit()
session.refresh(db_team)
return db_team
@app.delete("/teams/{team_id}")
def delete_team(*, session: Session = Depends(get_session), team_id: int):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
session.delete(team)
session.commit()
return {"ok": True}
from typing import Optional
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Relationship, Session, SQLModel, create_engine, select
class TeamBase(SQLModel):
name: str = Field(index=True)
headquarters: str
class Team(TeamBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
heroes: list["Hero"] = Relationship(back_populates="team")
class TeamCreate(TeamBase):
pass
class TeamPublic(TeamBase):
id: int
class TeamUpdate(SQLModel):
name: Optional[str] = None
headquarters: Optional[str] = None
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: Optional[int] = Field(default=None, index=True)
team_id: Optional[int] = Field(default=None, foreign_key="team.id")
class Hero(HeroBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
team: Optional[Team] = Relationship(back_populates="heroes")
class HeroPublic(HeroBase):
id: int
class HeroCreate(HeroBase):
pass
class HeroUpdate(SQLModel):
name: Optional[str] = None
secret_name: Optional[str] = None
age: Optional[int] = None
team_id: Optional[int] = None
sqlite_file_name = "database.db"
sqlite_url = f"sqlite:///{sqlite_file_name}"
connect_args = {"check_same_thread": False}
engine = create_engine(sqlite_url, echo=True, connect_args=connect_args)
def create_db_and_tables():
SQLModel.metadata.create_all(engine)
def get_session():
with Session(engine) as session:
yield session
app = FastAPI()
@app.on_event("startup")
def on_startup():
create_db_and_tables()
@app.post("/heroes/", response_model=HeroPublic)
def create_hero(*, session: Session = Depends(get_session), hero: HeroCreate):
db_hero = Hero.model_validate(hero)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
@app.get("/heroes/", response_model=list[HeroPublic])
def read_heroes(
*,
session: Session = Depends(get_session),
offset: int = 0,
limit: int = Query(default=100, le=100),
):
heroes = session.exec(select(Hero).offset(offset).limit(limit)).all()
return heroes
@app.get("/heroes/{hero_id}", response_model=HeroPublic)
def read_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
return hero
@app.patch("/heroes/{hero_id}", response_model=HeroPublic)
def update_hero(
*, session: Session = Depends(get_session), hero_id: int, hero: HeroUpdate
):
db_hero = session.get(Hero, hero_id)
if not db_hero:
raise HTTPException(status_code=404, detail="Hero not found")
hero_data = hero.model_dump(exclude_unset=True)
for key, value in hero_data.items():
setattr(db_hero, key, value)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
@app.delete("/heroes/{hero_id}")
def delete_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
session.delete(hero)
session.commit()
return {"ok": True}
@app.post("/teams/", response_model=TeamPublic)
def create_team(*, session: Session = Depends(get_session), team: TeamCreate):
db_team = Team.model_validate(team)
session.add(db_team)
session.commit()
session.refresh(db_team)
return db_team
@app.get("/teams/", response_model=list[TeamPublic])
def read_teams(
*,
session: Session = Depends(get_session),
offset: int = 0,
limit: int = Query(default=100, le=100),
):
teams = session.exec(select(Team).offset(offset).limit(limit)).all()
return teams
@app.get("/teams/{team_id}", response_model=TeamPublic)
def read_team(*, team_id: int, session: Session = Depends(get_session)):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
return team
@app.patch("/teams/{team_id}", response_model=TeamPublic)
def update_team(
*,
session: Session = Depends(get_session),
team_id: int,
team: TeamUpdate,
):
db_team = session.get(Team, team_id)
if not db_team:
raise HTTPException(status_code=404, detail="Team not found")
team_data = team.model_dump(exclude_unset=True)
for key, value in team_data.items():
setattr(db_team, key, value)
session.add(db_team)
session.commit()
session.refresh(db_team)
return db_team
@app.delete("/teams/{team_id}")
def delete_team(*, session: Session = Depends(get_session), team_id: int):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
session.delete(team)
session.commit()
return {"ok": True}
from typing import List, Optional
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Relationship, Session, SQLModel, create_engine, select
class TeamBase(SQLModel):
name: str = Field(index=True)
headquarters: str
class Team(TeamBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
heroes: List["Hero"] = Relationship(back_populates="team")
class TeamCreate(TeamBase):
pass
class TeamPublic(TeamBase):
id: int
class TeamUpdate(SQLModel):
name: Optional[str] = None
headquarters: Optional[str] = None
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: Optional[int] = Field(default=None, index=True)
team_id: Optional[int] = Field(default=None, foreign_key="team.id")
class Hero(HeroBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
team: Optional[Team] = Relationship(back_populates="heroes")
class HeroPublic(HeroBase):
id: int
class HeroCreate(HeroBase):
pass
class HeroUpdate(SQLModel):
name: Optional[str] = None
secret_name: Optional[str] = None
age: Optional[int] = None
team_id: Optional[int] = None
sqlite_file_name = "database.db"
sqlite_url = f"sqlite:///{sqlite_file_name}"
connect_args = {"check_same_thread": False}
engine = create_engine(sqlite_url, echo=True, connect_args=connect_args)
def create_db_and_tables():
SQLModel.metadata.create_all(engine)
def get_session():
with Session(engine) as session:
yield session
app = FastAPI()
@app.on_event("startup")
def on_startup():
create_db_and_tables()
@app.post("/heroes/", response_model=HeroPublic)
def create_hero(*, session: Session = Depends(get_session), hero: HeroCreate):
db_hero = Hero.model_validate(hero)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
@app.get("/heroes/", response_model=List[HeroPublic])
def read_heroes(
*,
session: Session = Depends(get_session),
offset: int = 0,
limit: int = Query(default=100, le=100),
):
heroes = session.exec(select(Hero).offset(offset).limit(limit)).all()
return heroes
@app.get("/heroes/{hero_id}", response_model=HeroPublic)
def read_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
return hero
@app.patch("/heroes/{hero_id}", response_model=HeroPublic)
def update_hero(
*, session: Session = Depends(get_session), hero_id: int, hero: HeroUpdate
):
db_hero = session.get(Hero, hero_id)
if not db_hero:
raise HTTPException(status_code=404, detail="Hero not found")
hero_data = hero.model_dump(exclude_unset=True)
for key, value in hero_data.items():
setattr(db_hero, key, value)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
@app.delete("/heroes/{hero_id}")
def delete_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
session.delete(hero)
session.commit()
return {"ok": True}
@app.post("/teams/", response_model=TeamPublic)
def create_team(*, session: Session = Depends(get_session), team: TeamCreate):
db_team = Team.model_validate(team)
session.add(db_team)
session.commit()
session.refresh(db_team)
return db_team
@app.get("/teams/", response_model=List[TeamPublic])
def read_teams(
*,
session: Session = Depends(get_session),
offset: int = 0,
limit: int = Query(default=100, le=100),
):
teams = session.exec(select(Team).offset(offset).limit(limit)).all()
return teams
@app.get("/teams/{team_id}", response_model=TeamPublic)
def read_team(*, team_id: int, session: Session = Depends(get_session)):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
return team
@app.patch("/teams/{team_id}", response_model=TeamPublic)
def update_team(
*,
session: Session = Depends(get_session),
team_id: int,
team: TeamUpdate,
):
db_team = session.get(Team, team_id)
if not db_team:
raise HTTPException(status_code=404, detail="Team not found")
team_data = team.model_dump(exclude_unset=True)
for key, value in team_data.items():
setattr(db_team, key, value)
session.add(db_team)
session.commit()
session.refresh(db_team)
return db_team
@app.delete("/teams/{team_id}")
def delete_team(*, session: Session = Depends(get_session), team_id: int):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
session.delete(team)
session.commit()
return {"ok": True}
ここで、FastAPIがレスポンスデータを検証およびフィルタリングするためにresponse_modelを使用していることを思い出してください。
この場合、response_model=TeamPublicおよびresponse_model=HeroPublicを使用したため、FastAPIはレスポンスデータをフィルタリングするためにそれらを使用します。たとえリレーションシップ属性を含むテーブルモデルを返してもです。
# Code above omitted 👆
@app.get("/heroes/{hero_id}", response_model=HeroPublic)
def read_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
return hero
# Code here omitted 👈
@app.get("/teams/{team_id}", response_model=TeamPublic)
def read_team(*, team_id: int, session: Session = Depends(get_session)):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
return team
# Code below omitted 👇
# Code above omitted 👆
@app.get("/heroes/{hero_id}", response_model=HeroPublic)
def read_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
return hero
# Code here omitted 👈
@app.get("/teams/{team_id}", response_model=TeamPublic)
def read_team(*, team_id: int, session: Session = Depends(get_session)):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
return team
# Code below omitted 👇
# Code above omitted 👆
@app.get("/heroes/{hero_id}", response_model=HeroPublic)
def read_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
return hero
# Code here omitted 👈
@app.get("/teams/{team_id}", response_model=TeamPublic)
def read_team(*, team_id: int, session: Session = Depends(get_session)):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
return team
# Code below omitted 👇
👀 ファイルの完全なプレビュー
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Relationship, Session, SQLModel, create_engine, select
class TeamBase(SQLModel):
name: str = Field(index=True)
headquarters: str
class Team(TeamBase, table=True):
id: int | None = Field(default=None, primary_key=True)
heroes: list["Hero"] = Relationship(back_populates="team")
class TeamCreate(TeamBase):
pass
class TeamPublic(TeamBase):
id: int
class TeamUpdate(SQLModel):
name: str | None = None
headquarters: str | None = None
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: int | None = Field(default=None, index=True)
team_id: int | None = Field(default=None, foreign_key="team.id")
class Hero(HeroBase, table=True):
id: int | None = Field(default=None, primary_key=True)
team: Team | None = Relationship(back_populates="heroes")
class HeroPublic(HeroBase):
id: int
class HeroCreate(HeroBase):
pass
class HeroUpdate(SQLModel):
name: str | None = None
secret_name: str | None = None
age: int | None = None
team_id: int | None = None
sqlite_file_name = "database.db"
sqlite_url = f"sqlite:///{sqlite_file_name}"
connect_args = {"check_same_thread": False}
engine = create_engine(sqlite_url, echo=True, connect_args=connect_args)
def create_db_and_tables():
SQLModel.metadata.create_all(engine)
def get_session():
with Session(engine) as session:
yield session
app = FastAPI()
@app.on_event("startup")
def on_startup():
create_db_and_tables()
@app.post("/heroes/", response_model=HeroPublic)
def create_hero(*, session: Session = Depends(get_session), hero: HeroCreate):
db_hero = Hero.model_validate(hero)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
@app.get("/heroes/", response_model=list[HeroPublic])
def read_heroes(
*,
session: Session = Depends(get_session),
offset: int = 0,
limit: int = Query(default=100, le=100),
):
heroes = session.exec(select(Hero).offset(offset).limit(limit)).all()
return heroes
@app.get("/heroes/{hero_id}", response_model=HeroPublic)
def read_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
return hero
@app.patch("/heroes/{hero_id}", response_model=HeroPublic)
def update_hero(
*, session: Session = Depends(get_session), hero_id: int, hero: HeroUpdate
):
db_hero = session.get(Hero, hero_id)
if not db_hero:
raise HTTPException(status_code=404, detail="Hero not found")
hero_data = hero.model_dump(exclude_unset=True)
for key, value in hero_data.items():
setattr(db_hero, key, value)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
@app.delete("/heroes/{hero_id}")
def delete_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
session.delete(hero)
session.commit()
return {"ok": True}
@app.post("/teams/", response_model=TeamPublic)
def create_team(*, session: Session = Depends(get_session), team: TeamCreate):
db_team = Team.model_validate(team)
session.add(db_team)
session.commit()
session.refresh(db_team)
return db_team
@app.get("/teams/", response_model=list[TeamPublic])
def read_teams(
*,
session: Session = Depends(get_session),
offset: int = 0,
limit: int = Query(default=100, le=100),
):
teams = session.exec(select(Team).offset(offset).limit(limit)).all()
return teams
@app.get("/teams/{team_id}", response_model=TeamPublic)
def read_team(*, team_id: int, session: Session = Depends(get_session)):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
return team
@app.patch("/teams/{team_id}", response_model=TeamPublic)
def update_team(
*,
session: Session = Depends(get_session),
team_id: int,
team: TeamUpdate,
):
db_team = session.get(Team, team_id)
if not db_team:
raise HTTPException(status_code=404, detail="Team not found")
team_data = team.model_dump(exclude_unset=True)
for key, value in team_data.items():
setattr(db_team, key, value)
session.add(db_team)
session.commit()
session.refresh(db_team)
return db_team
@app.delete("/teams/{team_id}")
def delete_team(*, session: Session = Depends(get_session), team_id: int):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
session.delete(team)
session.commit()
return {"ok": True}
from typing import Optional
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Relationship, Session, SQLModel, create_engine, select
class TeamBase(SQLModel):
name: str = Field(index=True)
headquarters: str
class Team(TeamBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
heroes: list["Hero"] = Relationship(back_populates="team")
class TeamCreate(TeamBase):
pass
class TeamPublic(TeamBase):
id: int
class TeamUpdate(SQLModel):
name: Optional[str] = None
headquarters: Optional[str] = None
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: Optional[int] = Field(default=None, index=True)
team_id: Optional[int] = Field(default=None, foreign_key="team.id")
class Hero(HeroBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
team: Optional[Team] = Relationship(back_populates="heroes")
class HeroPublic(HeroBase):
id: int
class HeroCreate(HeroBase):
pass
class HeroUpdate(SQLModel):
name: Optional[str] = None
secret_name: Optional[str] = None
age: Optional[int] = None
team_id: Optional[int] = None
sqlite_file_name = "database.db"
sqlite_url = f"sqlite:///{sqlite_file_name}"
connect_args = {"check_same_thread": False}
engine = create_engine(sqlite_url, echo=True, connect_args=connect_args)
def create_db_and_tables():
SQLModel.metadata.create_all(engine)
def get_session():
with Session(engine) as session:
yield session
app = FastAPI()
@app.on_event("startup")
def on_startup():
create_db_and_tables()
@app.post("/heroes/", response_model=HeroPublic)
def create_hero(*, session: Session = Depends(get_session), hero: HeroCreate):
db_hero = Hero.model_validate(hero)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
@app.get("/heroes/", response_model=list[HeroPublic])
def read_heroes(
*,
session: Session = Depends(get_session),
offset: int = 0,
limit: int = Query(default=100, le=100),
):
heroes = session.exec(select(Hero).offset(offset).limit(limit)).all()
return heroes
@app.get("/heroes/{hero_id}", response_model=HeroPublic)
def read_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
return hero
@app.patch("/heroes/{hero_id}", response_model=HeroPublic)
def update_hero(
*, session: Session = Depends(get_session), hero_id: int, hero: HeroUpdate
):
db_hero = session.get(Hero, hero_id)
if not db_hero:
raise HTTPException(status_code=404, detail="Hero not found")
hero_data = hero.model_dump(exclude_unset=True)
for key, value in hero_data.items():
setattr(db_hero, key, value)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
@app.delete("/heroes/{hero_id}")
def delete_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
session.delete(hero)
session.commit()
return {"ok": True}
@app.post("/teams/", response_model=TeamPublic)
def create_team(*, session: Session = Depends(get_session), team: TeamCreate):
db_team = Team.model_validate(team)
session.add(db_team)
session.commit()
session.refresh(db_team)
return db_team
@app.get("/teams/", response_model=list[TeamPublic])
def read_teams(
*,
session: Session = Depends(get_session),
offset: int = 0,
limit: int = Query(default=100, le=100),
):
teams = session.exec(select(Team).offset(offset).limit(limit)).all()
return teams
@app.get("/teams/{team_id}", response_model=TeamPublic)
def read_team(*, team_id: int, session: Session = Depends(get_session)):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
return team
@app.patch("/teams/{team_id}", response_model=TeamPublic)
def update_team(
*,
session: Session = Depends(get_session),
team_id: int,
team: TeamUpdate,
):
db_team = session.get(Team, team_id)
if not db_team:
raise HTTPException(status_code=404, detail="Team not found")
team_data = team.model_dump(exclude_unset=True)
for key, value in team_data.items():
setattr(db_team, key, value)
session.add(db_team)
session.commit()
session.refresh(db_team)
return db_team
@app.delete("/teams/{team_id}")
def delete_team(*, session: Session = Depends(get_session), team_id: int):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
session.delete(team)
session.commit()
return {"ok": True}
from typing import List, Optional
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Relationship, Session, SQLModel, create_engine, select
class TeamBase(SQLModel):
name: str = Field(index=True)
headquarters: str
class Team(TeamBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
heroes: List["Hero"] = Relationship(back_populates="team")
class TeamCreate(TeamBase):
pass
class TeamPublic(TeamBase):
id: int
class TeamUpdate(SQLModel):
name: Optional[str] = None
headquarters: Optional[str] = None
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: Optional[int] = Field(default=None, index=True)
team_id: Optional[int] = Field(default=None, foreign_key="team.id")
class Hero(HeroBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
team: Optional[Team] = Relationship(back_populates="heroes")
class HeroPublic(HeroBase):
id: int
class HeroCreate(HeroBase):
pass
class HeroUpdate(SQLModel):
name: Optional[str] = None
secret_name: Optional[str] = None
age: Optional[int] = None
team_id: Optional[int] = None
sqlite_file_name = "database.db"
sqlite_url = f"sqlite:///{sqlite_file_name}"
connect_args = {"check_same_thread": False}
engine = create_engine(sqlite_url, echo=True, connect_args=connect_args)
def create_db_and_tables():
SQLModel.metadata.create_all(engine)
def get_session():
with Session(engine) as session:
yield session
app = FastAPI()
@app.on_event("startup")
def on_startup():
create_db_and_tables()
@app.post("/heroes/", response_model=HeroPublic)
def create_hero(*, session: Session = Depends(get_session), hero: HeroCreate):
db_hero = Hero.model_validate(hero)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
@app.get("/heroes/", response_model=List[HeroPublic])
def read_heroes(
*,
session: Session = Depends(get_session),
offset: int = 0,
limit: int = Query(default=100, le=100),
):
heroes = session.exec(select(Hero).offset(offset).limit(limit)).all()
return heroes
@app.get("/heroes/{hero_id}", response_model=HeroPublic)
def read_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
return hero
@app.patch("/heroes/{hero_id}", response_model=HeroPublic)
def update_hero(
*, session: Session = Depends(get_session), hero_id: int, hero: HeroUpdate
):
db_hero = session.get(Hero, hero_id)
if not db_hero:
raise HTTPException(status_code=404, detail="Hero not found")
hero_data = hero.model_dump(exclude_unset=True)
for key, value in hero_data.items():
setattr(db_hero, key, value)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
@app.delete("/heroes/{hero_id}")
def delete_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
session.delete(hero)
session.commit()
return {"ok": True}
@app.post("/teams/", response_model=TeamPublic)
def create_team(*, session: Session = Depends(get_session), team: TeamCreate):
db_team = Team.model_validate(team)
session.add(db_team)
session.commit()
session.refresh(db_team)
return db_team
@app.get("/teams/", response_model=List[TeamPublic])
def read_teams(
*,
session: Session = Depends(get_session),
offset: int = 0,
limit: int = Query(default=100, le=100),
):
teams = session.exec(select(Team).offset(offset).limit(limit)).all()
return teams
@app.get("/teams/{team_id}", response_model=TeamPublic)
def read_team(*, team_id: int, session: Session = Depends(get_session)):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
return team
@app.patch("/teams/{team_id}", response_model=TeamPublic)
def update_team(
*,
session: Session = Depends(get_session),
team_id: int,
team: TeamUpdate,
):
db_team = session.get(Team, team_id)
if not db_team:
raise HTTPException(status_code=404, detail="Team not found")
team_data = team.model_dump(exclude_unset=True)
for key, value in team_data.items():
setattr(db_team, key, value)
session.add(db_team)
session.commit()
session.refresh(db_team)
return db_team
@app.delete("/teams/{team_id}")
def delete_team(*, session: Session = Depends(get_session), team_id: int):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
session.delete(team)
session.commit()
return {"ok": True}
すべてのデータを含めない¶
ここで少し立ち止まって考えてみましょう。
すべての内部リレーションシップを含むすべてのデータを単純に含めることはできません。なぜなら、各ヒーローにはチームを含む属性teamがあり、そのチームにもチームのすべてのヒーローを含む属性heroesがあるからです。これにはこのヒーローも含まれます。
すべてを含めようとすると、同じヒーローとチームを内部で何度も何度も繰り返して、無限のデータを抽出しようとしてサーバーアプリケーションがクラッシュする可能性があります。次のような感じです。
{
"name": "Rusty-Man",
"secret_name": "Tommy Sharp",
"age": 48,
"team_id": 1,
"id": 1,
"team": {
"name": "Preventers",
"headquarters": "Sharp Tower",
"id": 2,
"heroes": [
{
"name": "Rusty-Man",
"secret_name": "Tommy Sharp",
"age": 48,
"team_id": 1,
"id": 1,
"team": {
"name": "Preventers",
"headquarters": "Sharp Tower",
"id": 2,
"heroes": [
{
"name": "Rusty-Man",
"secret_name": "Tommy Sharp",
"age": 48,
"team_id": 1,
"id": 1,
"team": {
"name": "Preventers",
"headquarters": "Sharp Tower",
"id": 2,
"heroes": [
...with infinite data here... 😱
]
}
}
]
}
}
]
}
}
ご覧のとおり、この例では、ヒーローのRusty-Manを取得し、このヒーローからチームのPreventersを取得し、次にこのチームからそのヒーローを取得します。もちろん、Rusty-Manも含まれます。😱
そのため、最初からやり直すと、最終的にサーバーは"Maximum recursion error"でデータをすべて取得しようとしてクラッシュするだけで、上記のようなレスポンスすら取得できません。
そのため、どのケースでデータを含めるか、どのケースで含めないかを慎重に選択する必要があります。
含めるデータ¶
これは各アプリケーションによって決まる決定です。
私たちの場合、ヒーローのリストを取得する場合、それぞれのチームをそれぞれに含めたくはありません。
また、チームのリストを取得する場合、それぞれのヒーローのリストを取得したくはありません。
しかし、単一のヒーローを取得する場合は、チームデータを含めたいと思います(チームのヒーローを除く)。
また、単一のチームを取得する場合は、(各ヒーローのチームを除く)ヒーローのリストを含めたいと思います。
これらの2つの特定のパス操作で使用できるように、そのデータを宣言するいくつかのデータモデルを追加しましょう。
リレーションシップを持つモデル¶
HeroPublicWithTeamとTeamPublicWithHeroesモデルを追加しましょう。
以前のモデルを簡単に参照できるように、他のモデルの後に追加します。
# Code above omitted 👆
class HeroPublicWithTeam(HeroPublic):
team: TeamPublic | None = None
class TeamPublicWithHeroes(TeamPublic):
heroes: list[HeroPublic] = []
# Code below omitted 👇
# Code above omitted 👆
class HeroPublicWithTeam(HeroPublic):
team: Optional[TeamPublic] = None
class TeamPublicWithHeroes(TeamPublic):
heroes: list[HeroPublic] = []
# Code below omitted 👇
# Code above omitted 👆
class HeroPublicWithTeam(HeroPublic):
team: Optional[TeamPublic] = None
class TeamPublicWithHeroes(TeamPublic):
heroes: List[HeroPublic] = []
# Code below omitted 👇
👀 ファイルの完全なプレビュー
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Relationship, Session, SQLModel, create_engine, select
class TeamBase(SQLModel):
name: str = Field(index=True)
headquarters: str
class Team(TeamBase, table=True):
id: int | None = Field(default=None, primary_key=True)
heroes: list["Hero"] = Relationship(back_populates="team")
class TeamCreate(TeamBase):
pass
class TeamPublic(TeamBase):
id: int
class TeamUpdate(SQLModel):
id: int | None = None
name: str | None = None
headquarters: str | None = None
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: int | None = Field(default=None, index=True)
team_id: int | None = Field(default=None, foreign_key="team.id")
class Hero(HeroBase, table=True):
id: int | None = Field(default=None, primary_key=True)
team: Team | None = Relationship(back_populates="heroes")
class HeroPublic(HeroBase):
id: int
class HeroCreate(HeroBase):
pass
class HeroUpdate(SQLModel):
name: str | None = None
secret_name: str | None = None
age: int | None = None
team_id: int | None = None
class HeroPublicWithTeam(HeroPublic):
team: TeamPublic | None = None
class TeamPublicWithHeroes(TeamPublic):
heroes: list[HeroPublic] = []
sqlite_file_name = "database.db"
sqlite_url = f"sqlite:///{sqlite_file_name}"
connect_args = {"check_same_thread": False}
engine = create_engine(sqlite_url, echo=True, connect_args=connect_args)
def create_db_and_tables():
SQLModel.metadata.create_all(engine)
def get_session():
with Session(engine) as session:
yield session
app = FastAPI()
@app.on_event("startup")
def on_startup():
create_db_and_tables()
@app.post("/heroes/", response_model=HeroPublic)
def create_hero(*, session: Session = Depends(get_session), hero: HeroCreate):
db_hero = Hero.model_validate(hero)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
@app.get("/heroes/", response_model=list[HeroPublic])
def read_heroes(
*,
session: Session = Depends(get_session),
offset: int = 0,
limit: int = Query(default=100, le=100),
):
heroes = session.exec(select(Hero).offset(offset).limit(limit)).all()
return heroes
@app.get("/heroes/{hero_id}", response_model=HeroPublicWithTeam)
def read_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
return hero
@app.patch("/heroes/{hero_id}", response_model=HeroPublic)
def update_hero(
*, session: Session = Depends(get_session), hero_id: int, hero: HeroUpdate
):
db_hero = session.get(Hero, hero_id)
if not db_hero:
raise HTTPException(status_code=404, detail="Hero not found")
hero_data = hero.model_dump(exclude_unset=True)
for key, value in hero_data.items():
setattr(db_hero, key, value)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
@app.delete("/heroes/{hero_id}")
def delete_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
session.delete(hero)
session.commit()
return {"ok": True}
@app.post("/teams/", response_model=TeamPublic)
def create_team(*, session: Session = Depends(get_session), team: TeamCreate):
db_team = Team.model_validate(team)
session.add(db_team)
session.commit()
session.refresh(db_team)
return db_team
@app.get("/teams/", response_model=list[TeamPublic])
def read_teams(
*,
session: Session = Depends(get_session),
offset: int = 0,
limit: int = Query(default=100, le=100),
):
teams = session.exec(select(Team).offset(offset).limit(limit)).all()
return teams
@app.get("/teams/{team_id}", response_model=TeamPublicWithHeroes)
def read_team(*, team_id: int, session: Session = Depends(get_session)):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
return team
@app.patch("/teams/{team_id}", response_model=TeamPublic)
def update_team(
*,
session: Session = Depends(get_session),
team_id: int,
team: TeamUpdate,
):
db_team = session.get(Team, team_id)
if not db_team:
raise HTTPException(status_code=404, detail="Team not found")
team_data = team.model_dump(exclude_unset=True)
for key, value in team_data.items():
setattr(db_team, key, value)
session.add(db_team)
session.commit()
session.refresh(db_team)
return db_team
@app.delete("/teams/{team_id}")
def delete_team(*, session: Session = Depends(get_session), team_id: int):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
session.delete(team)
session.commit()
return {"ok": True}
from typing import Optional
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Relationship, Session, SQLModel, create_engine, select
class TeamBase(SQLModel):
name: str = Field(index=True)
headquarters: str
class Team(TeamBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
heroes: list["Hero"] = Relationship(back_populates="team")
class TeamCreate(TeamBase):
pass
class TeamPublic(TeamBase):
id: int
class TeamUpdate(SQLModel):
id: Optional[int] = None
name: Optional[str] = None
headquarters: Optional[str] = None
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: Optional[int] = Field(default=None, index=True)
team_id: Optional[int] = Field(default=None, foreign_key="team.id")
class Hero(HeroBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
team: Optional[Team] = Relationship(back_populates="heroes")
class HeroPublic(HeroBase):
id: int
class HeroCreate(HeroBase):
pass
class HeroUpdate(SQLModel):
name: Optional[str] = None
secret_name: Optional[str] = None
age: Optional[int] = None
team_id: Optional[int] = None
class HeroPublicWithTeam(HeroPublic):
team: Optional[TeamPublic] = None
class TeamPublicWithHeroes(TeamPublic):
heroes: list[HeroPublic] = []
sqlite_file_name = "database.db"
sqlite_url = f"sqlite:///{sqlite_file_name}"
connect_args = {"check_same_thread": False}
engine = create_engine(sqlite_url, echo=True, connect_args=connect_args)
def create_db_and_tables():
SQLModel.metadata.create_all(engine)
def get_session():
with Session(engine) as session:
yield session
app = FastAPI()
@app.on_event("startup")
def on_startup():
create_db_and_tables()
@app.post("/heroes/", response_model=HeroPublic)
def create_hero(*, session: Session = Depends(get_session), hero: HeroCreate):
db_hero = Hero.model_validate(hero)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
@app.get("/heroes/", response_model=list[HeroPublic])
def read_heroes(
*,
session: Session = Depends(get_session),
offset: int = 0,
limit: int = Query(default=100, le=100),
):
heroes = session.exec(select(Hero).offset(offset).limit(limit)).all()
return heroes
@app.get("/heroes/{hero_id}", response_model=HeroPublicWithTeam)
def read_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
return hero
@app.patch("/heroes/{hero_id}", response_model=HeroPublic)
def update_hero(
*, session: Session = Depends(get_session), hero_id: int, hero: HeroUpdate
):
db_hero = session.get(Hero, hero_id)
if not db_hero:
raise HTTPException(status_code=404, detail="Hero not found")
hero_data = hero.model_dump(exclude_unset=True)
for key, value in hero_data.items():
setattr(db_hero, key, value)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
@app.delete("/heroes/{hero_id}")
def delete_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
session.delete(hero)
session.commit()
return {"ok": True}
@app.post("/teams/", response_model=TeamPublic)
def create_team(*, session: Session = Depends(get_session), team: TeamCreate):
db_team = Team.model_validate(team)
session.add(db_team)
session.commit()
session.refresh(db_team)
return db_team
@app.get("/teams/", response_model=list[TeamPublic])
def read_teams(
*,
session: Session = Depends(get_session),
offset: int = 0,
limit: int = Query(default=100, le=100),
):
teams = session.exec(select(Team).offset(offset).limit(limit)).all()
return teams
@app.get("/teams/{team_id}", response_model=TeamPublicWithHeroes)
def read_team(*, team_id: int, session: Session = Depends(get_session)):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
return team
@app.patch("/teams/{team_id}", response_model=TeamPublic)
def update_team(
*,
session: Session = Depends(get_session),
team_id: int,
team: TeamUpdate,
):
db_team = session.get(Team, team_id)
if not db_team:
raise HTTPException(status_code=404, detail="Team not found")
team_data = team.model_dump(exclude_unset=True)
for key, value in team_data.items():
setattr(db_team, key, value)
session.add(db_team)
session.commit()
session.refresh(db_team)
return db_team
@app.delete("/teams/{team_id}")
def delete_team(*, session: Session = Depends(get_session), team_id: int):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
session.delete(team)
session.commit()
return {"ok": True}
from typing import List, Optional
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Relationship, Session, SQLModel, create_engine, select
class TeamBase(SQLModel):
name: str = Field(index=True)
headquarters: str
class Team(TeamBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
heroes: List["Hero"] = Relationship(back_populates="team")
class TeamCreate(TeamBase):
pass
class TeamPublic(TeamBase):
id: int
class TeamUpdate(SQLModel):
id: Optional[int] = None
name: Optional[str] = None
headquarters: Optional[str] = None
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: Optional[int] = Field(default=None, index=True)
team_id: Optional[int] = Field(default=None, foreign_key="team.id")
class Hero(HeroBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
team: Optional[Team] = Relationship(back_populates="heroes")
class HeroPublic(HeroBase):
id: int
class HeroCreate(HeroBase):
pass
class HeroUpdate(SQLModel):
name: Optional[str] = None
secret_name: Optional[str] = None
age: Optional[int] = None
team_id: Optional[int] = None
class HeroPublicWithTeam(HeroPublic):
team: Optional[TeamPublic] = None
class TeamPublicWithHeroes(TeamPublic):
heroes: List[HeroPublic] = []
sqlite_file_name = "database.db"
sqlite_url = f"sqlite:///{sqlite_file_name}"
connect_args = {"check_same_thread": False}
engine = create_engine(sqlite_url, echo=True, connect_args=connect_args)
def create_db_and_tables():
SQLModel.metadata.create_all(engine)
def get_session():
with Session(engine) as session:
yield session
app = FastAPI()
@app.on_event("startup")
def on_startup():
create_db_and_tables()
@app.post("/heroes/", response_model=HeroPublic)
def create_hero(*, session: Session = Depends(get_session), hero: HeroCreate):
db_hero = Hero.model_validate(hero)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
@app.get("/heroes/", response_model=List[HeroPublic])
def read_heroes(
*,
session: Session = Depends(get_session),
offset: int = 0,
limit: int = Query(default=100, le=100),
):
heroes = session.exec(select(Hero).offset(offset).limit(limit)).all()
return heroes
@app.get("/heroes/{hero_id}", response_model=HeroPublicWithTeam)
def read_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
return hero
@app.patch("/heroes/{hero_id}", response_model=HeroPublic)
def update_hero(
*, session: Session = Depends(get_session), hero_id: int, hero: HeroUpdate
):
db_hero = session.get(Hero, hero_id)
if not db_hero:
raise HTTPException(status_code=404, detail="Hero not found")
hero_data = hero.model_dump(exclude_unset=True)
for key, value in hero_data.items():
setattr(db_hero, key, value)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
@app.delete("/heroes/{hero_id}")
def delete_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
session.delete(hero)
session.commit()
return {"ok": True}
@app.post("/teams/", response_model=TeamPublic)
def create_team(*, session: Session = Depends(get_session), team: TeamCreate):
db_team = Team.model_validate(team)
session.add(db_team)
session.commit()
session.refresh(db_team)
return db_team
@app.get("/teams/", response_model=List[TeamPublic])
def read_teams(
*,
session: Session = Depends(get_session),
offset: int = 0,
limit: int = Query(default=100, le=100),
):
teams = session.exec(select(Team).offset(offset).limit(limit)).all()
return teams
@app.get("/teams/{team_id}", response_model=TeamPublicWithHeroes)
def read_team(*, team_id: int, session: Session = Depends(get_session)):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
return team
@app.patch("/teams/{team_id}", response_model=TeamPublic)
def update_team(
*,
session: Session = Depends(get_session),
team_id: int,
team: TeamUpdate,
):
db_team = session.get(Team, team_id)
if not db_team:
raise HTTPException(status_code=404, detail="Team not found")
team_data = team.model_dump(exclude_unset=True)
for key, value in team_data.items():
setattr(db_team, key, value)
session.add(db_team)
session.commit()
session.refresh(db_team)
return db_team
@app.delete("/teams/{team_id}")
def delete_team(*, session: Session = Depends(get_session), team_id: int):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
session.delete(team)
session.commit()
return {"ok": True}
これらの2つのモデルはコードが非常にシンプルですが、ここでは多くのことが起こっています。確認してみましょう。
継承と型アノテーション¶
HeroPublicWithTeamはHeroPublicを継承しており、これはHeroPublicで宣言された必須のidを含め、読み取り用の通常のフィールドを持つことを意味します。
そして、Noneになる可能性があり、チームを読み取るための基本フィールドを持つ型TeamPublicで宣言された新しいフィールドteamを追加します。
次に、TeamPublicWithHeroesについても同様に行います。TeamPublicを継承し、HeroPublicのリストである新しいフィールドheroesを宣言します。
リレーションシップ属性のないデータモデル¶
ここで、これらの新しいフィールドteamとheroesはRelationship()で宣言されていないことに注意してください。これは、これらがテーブルモデルではなく、データベースからそのデータを取得するための魔法のアクセスを備えたリレーションシップ属性を持つことができないためです。
代わりに、ここではこれらは単なるデータモデルであり、FastAPIにデータを取得する属性と、そこから取得するデータを伝えます。
他のモデルへの参照¶
また、フィールドteamがこの新しいTeamPublicWithHeroesで宣言されていないことにも注意してください。なぜなら、それは再びデータの無限再帰を作成するからです。代わりに、通常のTeamPublicモデルで宣言します。
また、TeamPublicWithHeroesについても同様です。新しいフィールドheroesに使用されるモデルは、各ヒーローのデータのみを取得するためにHeroPublicを使用します。
これは、これらの2つの新しいモデルがある場合でも、以前のモデルであるHeroPublicとTeamPublicが依然として必要であることを意味します。なぜなら、ここでそれらを参照する必要があるからです(また、残りのパス操作でも使用しています)。
パス操作を更新する¶
これで、新しいモデルを使用するようにパス操作を更新できます。
これにより、FastAPIは、パス操作関数(テーブルモデル)から返されるオブジェクトを取得し、それらからデータを抽出するために追加の属性にアクセスするようになります。
ヒーローの場合、これはFastAPIにteamも抽出するように指示します。また、チームの場合、heroesのリストも抽出するように指示します。
# Code above omitted 👆
@app.get("/heroes/{hero_id}", response_model=HeroPublicWithTeam)
def read_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
return hero
# Code here omitted 👈
@app.get("/teams/{team_id}", response_model=TeamPublicWithHeroes)
def read_team(*, team_id: int, session: Session = Depends(get_session)):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
return team
# Code below omitted 👇
# Code above omitted 👆
@app.get("/heroes/{hero_id}", response_model=HeroPublicWithTeam)
def read_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
return hero
# Code here omitted 👈
@app.get("/teams/{team_id}", response_model=TeamPublicWithHeroes)
def read_team(*, team_id: int, session: Session = Depends(get_session)):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
return team
# Code below omitted 👇
# Code above omitted 👆
@app.get("/heroes/{hero_id}", response_model=HeroPublicWithTeam)
def read_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
return hero
# Code here omitted 👈
@app.get("/teams/{team_id}", response_model=TeamPublicWithHeroes)
def read_team(*, team_id: int, session: Session = Depends(get_session)):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
return team
# Code below omitted 👇
👀 ファイルの完全なプレビュー
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Relationship, Session, SQLModel, create_engine, select
class TeamBase(SQLModel):
name: str = Field(index=True)
headquarters: str
class Team(TeamBase, table=True):
id: int | None = Field(default=None, primary_key=True)
heroes: list["Hero"] = Relationship(back_populates="team")
class TeamCreate(TeamBase):
pass
class TeamPublic(TeamBase):
id: int
class TeamUpdate(SQLModel):
id: int | None = None
name: str | None = None
headquarters: str | None = None
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: int | None = Field(default=None, index=True)
team_id: int | None = Field(default=None, foreign_key="team.id")
class Hero(HeroBase, table=True):
id: int | None = Field(default=None, primary_key=True)
team: Team | None = Relationship(back_populates="heroes")
class HeroPublic(HeroBase):
id: int
class HeroCreate(HeroBase):
pass
class HeroUpdate(SQLModel):
name: str | None = None
secret_name: str | None = None
age: int | None = None
team_id: int | None = None
class HeroPublicWithTeam(HeroPublic):
team: TeamPublic | None = None
class TeamPublicWithHeroes(TeamPublic):
heroes: list[HeroPublic] = []
sqlite_file_name = "database.db"
sqlite_url = f"sqlite:///{sqlite_file_name}"
connect_args = {"check_same_thread": False}
engine = create_engine(sqlite_url, echo=True, connect_args=connect_args)
def create_db_and_tables():
SQLModel.metadata.create_all(engine)
def get_session():
with Session(engine) as session:
yield session
app = FastAPI()
@app.on_event("startup")
def on_startup():
create_db_and_tables()
@app.post("/heroes/", response_model=HeroPublic)
def create_hero(*, session: Session = Depends(get_session), hero: HeroCreate):
db_hero = Hero.model_validate(hero)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
@app.get("/heroes/", response_model=list[HeroPublic])
def read_heroes(
*,
session: Session = Depends(get_session),
offset: int = 0,
limit: int = Query(default=100, le=100),
):
heroes = session.exec(select(Hero).offset(offset).limit(limit)).all()
return heroes
@app.get("/heroes/{hero_id}", response_model=HeroPublicWithTeam)
def read_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
return hero
@app.patch("/heroes/{hero_id}", response_model=HeroPublic)
def update_hero(
*, session: Session = Depends(get_session), hero_id: int, hero: HeroUpdate
):
db_hero = session.get(Hero, hero_id)
if not db_hero:
raise HTTPException(status_code=404, detail="Hero not found")
hero_data = hero.model_dump(exclude_unset=True)
for key, value in hero_data.items():
setattr(db_hero, key, value)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
@app.delete("/heroes/{hero_id}")
def delete_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
session.delete(hero)
session.commit()
return {"ok": True}
@app.post("/teams/", response_model=TeamPublic)
def create_team(*, session: Session = Depends(get_session), team: TeamCreate):
db_team = Team.model_validate(team)
session.add(db_team)
session.commit()
session.refresh(db_team)
return db_team
@app.get("/teams/", response_model=list[TeamPublic])
def read_teams(
*,
session: Session = Depends(get_session),
offset: int = 0,
limit: int = Query(default=100, le=100),
):
teams = session.exec(select(Team).offset(offset).limit(limit)).all()
return teams
@app.get("/teams/{team_id}", response_model=TeamPublicWithHeroes)
def read_team(*, team_id: int, session: Session = Depends(get_session)):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
return team
@app.patch("/teams/{team_id}", response_model=TeamPublic)
def update_team(
*,
session: Session = Depends(get_session),
team_id: int,
team: TeamUpdate,
):
db_team = session.get(Team, team_id)
if not db_team:
raise HTTPException(status_code=404, detail="Team not found")
team_data = team.model_dump(exclude_unset=True)
for key, value in team_data.items():
setattr(db_team, key, value)
session.add(db_team)
session.commit()
session.refresh(db_team)
return db_team
@app.delete("/teams/{team_id}")
def delete_team(*, session: Session = Depends(get_session), team_id: int):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
session.delete(team)
session.commit()
return {"ok": True}
from typing import Optional
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Relationship, Session, SQLModel, create_engine, select
class TeamBase(SQLModel):
name: str = Field(index=True)
headquarters: str
class Team(TeamBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
heroes: list["Hero"] = Relationship(back_populates="team")
class TeamCreate(TeamBase):
pass
class TeamPublic(TeamBase):
id: int
class TeamUpdate(SQLModel):
id: Optional[int] = None
name: Optional[str] = None
headquarters: Optional[str] = None
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: Optional[int] = Field(default=None, index=True)
team_id: Optional[int] = Field(default=None, foreign_key="team.id")
class Hero(HeroBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
team: Optional[Team] = Relationship(back_populates="heroes")
class HeroPublic(HeroBase):
id: int
class HeroCreate(HeroBase):
pass
class HeroUpdate(SQLModel):
name: Optional[str] = None
secret_name: Optional[str] = None
age: Optional[int] = None
team_id: Optional[int] = None
class HeroPublicWithTeam(HeroPublic):
team: Optional[TeamPublic] = None
class TeamPublicWithHeroes(TeamPublic):
heroes: list[HeroPublic] = []
sqlite_file_name = "database.db"
sqlite_url = f"sqlite:///{sqlite_file_name}"
connect_args = {"check_same_thread": False}
engine = create_engine(sqlite_url, echo=True, connect_args=connect_args)
def create_db_and_tables():
SQLModel.metadata.create_all(engine)
def get_session():
with Session(engine) as session:
yield session
app = FastAPI()
@app.on_event("startup")
def on_startup():
create_db_and_tables()
@app.post("/heroes/", response_model=HeroPublic)
def create_hero(*, session: Session = Depends(get_session), hero: HeroCreate):
db_hero = Hero.model_validate(hero)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
@app.get("/heroes/", response_model=list[HeroPublic])
def read_heroes(
*,
session: Session = Depends(get_session),
offset: int = 0,
limit: int = Query(default=100, le=100),
):
heroes = session.exec(select(Hero).offset(offset).limit(limit)).all()
return heroes
@app.get("/heroes/{hero_id}", response_model=HeroPublicWithTeam)
def read_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
return hero
@app.patch("/heroes/{hero_id}", response_model=HeroPublic)
def update_hero(
*, session: Session = Depends(get_session), hero_id: int, hero: HeroUpdate
):
db_hero = session.get(Hero, hero_id)
if not db_hero:
raise HTTPException(status_code=404, detail="Hero not found")
hero_data = hero.model_dump(exclude_unset=True)
for key, value in hero_data.items():
setattr(db_hero, key, value)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
@app.delete("/heroes/{hero_id}")
def delete_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
session.delete(hero)
session.commit()
return {"ok": True}
@app.post("/teams/", response_model=TeamPublic)
def create_team(*, session: Session = Depends(get_session), team: TeamCreate):
db_team = Team.model_validate(team)
session.add(db_team)
session.commit()
session.refresh(db_team)
return db_team
@app.get("/teams/", response_model=list[TeamPublic])
def read_teams(
*,
session: Session = Depends(get_session),
offset: int = 0,
limit: int = Query(default=100, le=100),
):
teams = session.exec(select(Team).offset(offset).limit(limit)).all()
return teams
@app.get("/teams/{team_id}", response_model=TeamPublicWithHeroes)
def read_team(*, team_id: int, session: Session = Depends(get_session)):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
return team
@app.patch("/teams/{team_id}", response_model=TeamPublic)
def update_team(
*,
session: Session = Depends(get_session),
team_id: int,
team: TeamUpdate,
):
db_team = session.get(Team, team_id)
if not db_team:
raise HTTPException(status_code=404, detail="Team not found")
team_data = team.model_dump(exclude_unset=True)
for key, value in team_data.items():
setattr(db_team, key, value)
session.add(db_team)
session.commit()
session.refresh(db_team)
return db_team
@app.delete("/teams/{team_id}")
def delete_team(*, session: Session = Depends(get_session), team_id: int):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
session.delete(team)
session.commit()
return {"ok": True}
from typing import List, Optional
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Relationship, Session, SQLModel, create_engine, select
class TeamBase(SQLModel):
name: str = Field(index=True)
headquarters: str
class Team(TeamBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
heroes: List["Hero"] = Relationship(back_populates="team")
class TeamCreate(TeamBase):
pass
class TeamPublic(TeamBase):
id: int
class TeamUpdate(SQLModel):
id: Optional[int] = None
name: Optional[str] = None
headquarters: Optional[str] = None
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: Optional[int] = Field(default=None, index=True)
team_id: Optional[int] = Field(default=None, foreign_key="team.id")
class Hero(HeroBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
team: Optional[Team] = Relationship(back_populates="heroes")
class HeroPublic(HeroBase):
id: int
class HeroCreate(HeroBase):
pass
class HeroUpdate(SQLModel):
name: Optional[str] = None
secret_name: Optional[str] = None
age: Optional[int] = None
team_id: Optional[int] = None
class HeroPublicWithTeam(HeroPublic):
team: Optional[TeamPublic] = None
class TeamPublicWithHeroes(TeamPublic):
heroes: List[HeroPublic] = []
sqlite_file_name = "database.db"
sqlite_url = f"sqlite:///{sqlite_file_name}"
connect_args = {"check_same_thread": False}
engine = create_engine(sqlite_url, echo=True, connect_args=connect_args)
def create_db_and_tables():
SQLModel.metadata.create_all(engine)
def get_session():
with Session(engine) as session:
yield session
app = FastAPI()
@app.on_event("startup")
def on_startup():
create_db_and_tables()
@app.post("/heroes/", response_model=HeroPublic)
def create_hero(*, session: Session = Depends(get_session), hero: HeroCreate):
db_hero = Hero.model_validate(hero)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
@app.get("/heroes/", response_model=List[HeroPublic])
def read_heroes(
*,
session: Session = Depends(get_session),
offset: int = 0,
limit: int = Query(default=100, le=100),
):
heroes = session.exec(select(Hero).offset(offset).limit(limit)).all()
return heroes
@app.get("/heroes/{hero_id}", response_model=HeroPublicWithTeam)
def read_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
return hero
@app.patch("/heroes/{hero_id}", response_model=HeroPublic)
def update_hero(
*, session: Session = Depends(get_session), hero_id: int, hero: HeroUpdate
):
db_hero = session.get(Hero, hero_id)
if not db_hero:
raise HTTPException(status_code=404, detail="Hero not found")
hero_data = hero.model_dump(exclude_unset=True)
for key, value in hero_data.items():
setattr(db_hero, key, value)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
@app.delete("/heroes/{hero_id}")
def delete_hero(*, session: Session = Depends(get_session), hero_id: int):
hero = session.get(Hero, hero_id)
if not hero:
raise HTTPException(status_code=404, detail="Hero not found")
session.delete(hero)
session.commit()
return {"ok": True}
@app.post("/teams/", response_model=TeamPublic)
def create_team(*, session: Session = Depends(get_session), team: TeamCreate):
db_team = Team.model_validate(team)
session.add(db_team)
session.commit()
session.refresh(db_team)
return db_team
@app.get("/teams/", response_model=List[TeamPublic])
def read_teams(
*,
session: Session = Depends(get_session),
offset: int = 0,
limit: int = Query(default=100, le=100),
):
teams = session.exec(select(Team).offset(offset).limit(limit)).all()
return teams
@app.get("/teams/{team_id}", response_model=TeamPublicWithHeroes)
def read_team(*, team_id: int, session: Session = Depends(get_session)):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
return team
@app.patch("/teams/{team_id}", response_model=TeamPublic)
def update_team(
*,
session: Session = Depends(get_session),
team_id: int,
team: TeamUpdate,
):
db_team = session.get(Team, team_id)
if not db_team:
raise HTTPException(status_code=404, detail="Team not found")
team_data = team.model_dump(exclude_unset=True)
for key, value in team_data.items():
setattr(db_team, key, value)
session.add(db_team)
session.commit()
session.refresh(db_team)
return db_team
@app.delete("/teams/{team_id}")
def delete_team(*, session: Session = Depends(get_session), team_id: int):
team = session.get(Team, team_id)
if not team:
raise HTTPException(status_code=404, detail="Team not found")
session.delete(team)
session.commit()
return {"ok": True}
ドキュメントUIで確認する¶
ここで、もう一度ドキュメントUIで試してみましょう。
IDが1の同じヒーローをもう一度試してみましょう

これで、チームデータが含まれて取得されます
{
"name": "Deadpond",
"secret_name": "Dive Wilson",
"age": null,
"team_id": 1,
"id": 1,
"team": {
"name": "Z-Force",
"headquarters": "Sister Margaret's Bar",
"id": 1
}
}
次に、IDが2のチームを取得すると

これで、ヒーローのリストが含まれて取得されます
{
"name": "Preventers",
"headquarters": "Sharp Tower",
"id": 2,
"heroes": [
{
"name": "Rusty-Man",
"secret_name": "Tommy Sharp",
"age": 48,
"team_id": 2,
"id": 2
},
{
"name": "Spider-Boy",
"secret_name": "Pedro Parqueador",
"age": null,
"team_id": 2,
"id": 3
},
{
"name": "Tarantula",
"secret_name": "Natalia Roman-on",
"age": 32,
"team_id": 2,
"id": 6
},
{
"name": "Dr. Weird",
"secret_name": "Steve Weird",
"age": 36,
"team_id": 2,
"id": 7
},
{
"name": "Captain North America",
"secret_name": "Esteban Rogelios",
"age": 93,
"team_id": 2,
"id": 8
}
]
}
要約¶
追加のデータモデルを宣言する同じ手法を使用して、テーブルモデルを返す場合でも、FastAPIに応答で返すデータを伝えることができます。
ここでは、FastAPIアプリのコードをほとんど変更する必要はありませんでした。しかしもちろん、データを取得し、それをパス操作関数内で異なる方法で処理してから返す必要があるケースも出てくるでしょう。
しかし、そのような場合でも、response_modelで利用するデータモデルを定義して、FastAPIにデータの検証とフィルタリングの方法を指示することができます。
ここまでで、SQLModelとFastAPIを組み合わせ、データ検証、変換、フィルタリング、ドキュメント化といったベストプラクティスを実装することにより、SQLデータベース内のデータを処理するための非常に堅牢なAPIが既に完成しました。✨
次の章では、FastAPIとSQLModelを使用して、アプリケーションの自動テストを実装する方法について説明します。✅