使用 FastAPI 依赖项管理 Session¶
在我们继续添加功能之前，让我们稍微改变一下获取每个请求的 session 的方式，以便以后简化我们的工作。
当前的 Session¶
到目前为止，我们在每个 路径操作 中都在 with 块中创建了一个 session。
# 代码省略 👆
@app.post("/heroes/", response_model=HeroPublic)
def create_hero(hero: HeroCreate):
with Session(engine) as session:
db_hero = Hero.model_validate(hero)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
# 代码省略 👇
# 代码省略 👆
@app.post("/heroes/", response_model=HeroPublic)
def create_hero(hero: HeroCreate):
with Session(engine) as session:
db_hero = Hero.model_validate(hero)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
# 代码省略 👇
# 代码省略 👆
@app.post("/heroes/", response_model=HeroPublic)
def create_hero(hero: HeroCreate):
with Session(engine) as session:
db_hero = Hero.model_validate(hero)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
# 代码省略 👇
👀 完整文件预览
from fastapi import FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: int | None = Field(default=None, index=True)
class Hero(HeroBase, table=True):
id: int | None = Field(default=None, primary_key=True)
class HeroCreate(HeroBase):
pass
class HeroPublic(HeroBase):
id: int
class HeroUpdate(SQLModel):
name: str | None = None
secret_name: str | None = None
age: 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)
app = FastAPI()
@app.on_event("startup")
def on_startup():
create_db_and_tables()
@app.post("/heroes/", response_model=HeroPublic)
def create_hero(hero: HeroCreate):
with Session(engine) as session:
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(offset: int = 0, limit: int = Query(default=100, le=100)):
with Session(engine) as session:
heroes = session.exec(select(Hero).offset(offset).limit(limit)).all()
return heroes
@app.get("/heroes/{hero_id}", response_model=HeroPublic)
def read_hero(hero_id: int):
with Session(engine) as session:
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(hero_id: int, hero: HeroUpdate):
with Session(engine) as session:
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(hero_id: int):
with Session(engine) as session:
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}
from typing import Optional
from fastapi import FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: Optional[int] = Field(default=None, index=True)
class Hero(HeroBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
class HeroCreate(HeroBase):
pass
class HeroPublic(HeroBase):
id: int
class HeroUpdate(SQLModel):
name: Optional[str] = None
secret_name: Optional[str] = None
age: 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)
app = FastAPI()
@app.on_event("startup")
def on_startup():
create_db_and_tables()
@app.post("/heroes/", response_model=HeroPublic)
def create_hero(hero: HeroCreate):
with Session(engine) as session:
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(offset: int = 0, limit: int = Query(default=100, le=100)):
with Session(engine) as session:
heroes = session.exec(select(Hero).offset(offset).limit(limit)).all()
return heroes
@app.get("/heroes/{hero_id}", response_model=HeroPublic)
def read_hero(hero_id: int):
with Session(engine) as session:
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(hero_id: int, hero: HeroUpdate):
with Session(engine) as session:
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(hero_id: int):
with Session(engine) as session:
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}
from typing import List, Optional
from fastapi import FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: Optional[int] = Field(default=None, index=True)
class Hero(HeroBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
class HeroCreate(HeroBase):
pass
class HeroPublic(HeroBase):
id: int
class HeroUpdate(SQLModel):
name: Optional[str] = None
secret_name: Optional[str] = None
age: 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)
app = FastAPI()
@app.on_event("startup")
def on_startup():
create_db_and_tables()
@app.post("/heroes/", response_model=HeroPublic)
def create_hero(hero: HeroCreate):
with Session(engine) as session:
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(offset: int = 0, limit: int = Query(default=100, le=100)):
with Session(engine) as session:
heroes = session.exec(select(Hero).offset(offset).limit(limit)).all()
return heroes
@app.get("/heroes/{hero_id}", response_model=HeroPublic)
def read_hero(hero_id: int):
with Session(engine) as session:
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(hero_id: int, hero: HeroUpdate):
with Session(engine) as session:
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(hero_id: int):
with Session(engine) as session:
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}
这样做是完全没问题的，但在许多情况下，我们希望使用 FastAPI 依赖项，例如在执行任何其他代码之前， 验证 客户端是否 登录 并获取 当前用户 。
这些依赖项在 测试 中也非常有用，因为我们可以 轻松地替换它们，然后例如为测试使用新的数据库，或在测试前插入一些数据等。
因此，让我们重构这些 session，使其使用 FastAPI 依赖项。
创建一个 FastAPI 依赖项¶
FastAPI 依赖项非常简单，它只是一个返回值的函数。
它可以使用 yield 替代 return，在这种情况下，FastAPI 会确保在请求完成后执行所有 yield 之后的代码。
# 代码省略 👆
def get_session():
with Session(engine) as session:
yield session
# 代码省略 👇
# 代码省略 👆
def get_session():
with Session(engine) as session:
yield session
# 代码省略 👇
# 代码省略 👆
def get_session():
with Session(engine) as session:
yield session
# 代码省略 👇
👀 完整文件预览
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: int | None = Field(default=None, index=True)
class Hero(HeroBase, table=True):
id: int | None = Field(default=None, primary_key=True)
class HeroCreate(HeroBase):
pass
class HeroPublic(HeroBase):
id: int
class HeroUpdate(SQLModel):
name: str | None = None
secret_name: str | None = None
age: 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}
from typing import Optional
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: Optional[int] = Field(default=None, index=True)
class Hero(HeroBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
class HeroCreate(HeroBase):
pass
class HeroPublic(HeroBase):
id: int
class HeroUpdate(SQLModel):
name: Optional[str] = None
secret_name: Optional[str] = None
age: 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}
from typing import List, Optional
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: Optional[int] = Field(default=None, index=True)
class Hero(HeroBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
class HeroCreate(HeroBase):
pass
class HeroPublic(HeroBase):
id: int
class HeroUpdate(SQLModel):
name: Optional[str] = None
secret_name: Optional[str] = None
age: 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}
使用依赖项¶
现在，让我们让 FastAPI 执行一个依赖项，并在 路径操作 中获取它的值。
我们从 fastapi 导入 Depends()，然后在 路径操作函数 中使用它作为一个 参数，就像我们声明参数以获取 JSON 数据体、路径参数等一样。
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
# 代码省略 👈
def get_session():
with Session(engine) as session:
yield session
# 代码省略 👈
@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
# 代码省略 👇
from typing import Optional
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
# 代码省略 👈
def get_session():
with Session(engine) as session:
yield session
# 代码省略 👈
@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
# 代码省略 👇
from typing import List, Optional
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
# 代码省略 👈
def get_session():
with Session(engine) as session:
yield session
# 代码省略 👈
@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
# 代码省略 👇
👀 完整文件预览
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: int | None = Field(default=None, index=True)
class Hero(HeroBase, table=True):
id: int | None = Field(default=None, primary_key=True)
class HeroCreate(HeroBase):
pass
class HeroPublic(HeroBase):
id: int
class HeroUpdate(SQLModel):
name: str | None = None
secret_name: str | None = None
age: 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}
from typing import Optional
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: Optional[int] = Field(default=None, index=True)
class Hero(HeroBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
class HeroCreate(HeroBase):
pass
class HeroPublic(HeroBase):
id: int
class HeroUpdate(SQLModel):
name: Optional[str] = None
secret_name: Optional[str] = None
age: 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}
from typing import List, Optional
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: Optional[int] = Field(default=None, index=True)
class Hero(HeroBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
class HeroCreate(HeroBase):
pass
class HeroPublic(HeroBase):
id: int
class HeroUpdate(SQLModel):
name: Optional[str] = None
secret_name: Optional[str] = None
age: 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}
Tip
这里有一个关于参数中 *, 的小贴士。
在这里，我们传递了一个参数 session，它的“默认值”是 Depends(get_session)，位于没有默认值的参数 hero 之前。
通常情况下，Python 会抱怨这个，但我们可以使用初始的“参数” *, 来将剩下的参数标记为“仅限关键字”，这样就解决了这个问题。
你可以在 FastAPI 文档中阅读更多关于这个的内容：路径参数和数字验证 - 按需排序参数技巧
依赖项的值 只会用于一次请求，FastAPI 会在调用你的代码之前调用它，并将依赖项的值传递给你。
如果它有 yield，那么在你完成发送响应后，FastAPI 会继续执行 yield 之后的其余代码。在 session 的情况下，它会完成 with 块中的清理代码，关闭 session 等。
然后，FastAPI 会在 下一个请求 时再次调用它。
由于它是 每次请求调用一次，我们仍然会为每个请求获取 单个 session，因此我们仍然是可以接受的。✅
因为依赖项可以使用 yield，FastAPI 会确保在完成后运行 yield 之后的代码，包括 with 块末尾的所有 清理代码。所以我们也可以接受这一点。✅
with 块¶
这意味着在 路径操作函数 的主代码中，它将与之前使用显式 with 块的版本等效。
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
# 代码省略 👈
def get_session():
with Session(engine) as session:
yield session
# 代码省略 👈
@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
# 代码省略 👇
from typing import Optional
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
# 代码省略 👈
def get_session():
with Session(engine) as session:
yield session
# 代码省略 👈
@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
# 代码省略 👇
from typing import List, Optional
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
# 代码省略 👈
def get_session():
with Session(engine) as session:
yield session
# 代码省略 👈
@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
# 代码省略 👇
👀 完整文件预览
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: int | None = Field(default=None, index=True)
class Hero(HeroBase, table=True):
id: int | None = Field(default=None, primary_key=True)
class HeroCreate(HeroBase):
pass
class HeroPublic(HeroBase):
id: int
class HeroUpdate(SQLModel):
name: str | None = None
secret_name: str | None = None
age: 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}
from typing import Optional
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: Optional[int] = Field(default=None, index=True)
class Hero(HeroBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
class HeroCreate(HeroBase):
pass
class HeroPublic(HeroBase):
id: int
class HeroUpdate(SQLModel):
name: Optional[str] = None
secret_name: Optional[str] = None
age: 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}
from typing import List, Optional
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: Optional[int] = Field(default=None, index=True)
class Hero(HeroBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
class HeroCreate(HeroBase):
pass
class HeroPublic(HeroBase):
id: int
class HeroUpdate(SQLModel):
name: Optional[str] = None
secret_name: Optional[str] = None
age: 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}
实际上，你可以认为 create_hero() 函数中所有的代码块仍然是在 session 的 with 块内，因为这基本上是幕后发生的事情。
但现在，with 块并不显式在函数内，而是在上面的依赖项中：
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
# 代码省略 👈
def get_session():
with Session(engine) as session:
yield session
# 代码省略 👈
@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
# 代码省略 👇
from typing import Optional
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
# 代码省略 👈
def get_session():
with Session(engine) as session:
yield session
# 代码省略 👈
@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
# 代码省略 👇
from typing import List, Optional
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
# 代码省略 👈
def get_session():
with Session(engine) as session:
yield session
# 代码省略 👈
@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
# 代码省略 👇
👀 完整文件预览
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: int | None = Field(default=None, index=True)
class Hero(HeroBase, table=True):
id: int | None = Field(default=None, primary_key=True)
class HeroCreate(HeroBase):
pass
class HeroPublic(HeroBase):
id: int
class HeroUpdate(SQLModel):
name: str | None = None
secret_name: str | None = None
age: 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}
from typing import Optional
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: Optional[int] = Field(default=None, index=True)
class Hero(HeroBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
class HeroCreate(HeroBase):
pass
class HeroPublic(HeroBase):
id: int
class HeroUpdate(SQLModel):
name: Optional[str] = None
secret_name: Optional[str] = None
age: 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}
from typing import List, Optional
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: Optional[int] = Field(default=None, index=True)
class Hero(HeroBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
class HeroCreate(HeroBase):
pass
class HeroPublic(HeroBase):
id: int
class HeroUpdate(SQLModel):
name: Optional[str] = None
secret_name: Optional[str] = None
age: 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}
我们稍后会看到，这在测试代码时非常有用。✅
更新路径操作以使用依赖项¶
现在，我们可以更新其余的 路径操作 以使用新的依赖项。
我们只需在函数的参数中声明依赖项，使用：
session: Session = Depends(get_session)
然后，移除之前使用旧 session 的 with 块。
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
# 代码省略 👈
def get_session():
with Session(engine) as session:
yield session
# 代码省略 👈
@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}
from typing import Optional
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
# 代码省略 👈
def get_session():
with Session(engine) as session:
yield session
# 代码省略 👈
@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}
from typing import List, Optional
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
# 代码省略 👈
def get_session():
with Session(engine) as session:
yield session
# 代码省略 👈
@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}
👀 完整文件预览
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: int | None = Field(default=None, index=True)
class Hero(HeroBase, table=True):
id: int | None = Field(default=None, primary_key=True)
class HeroCreate(HeroBase):
pass
class HeroPublic(HeroBase):
id: int
class HeroUpdate(SQLModel):
name: str | None = None
secret_name: str | None = None
age: 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}
from typing import Optional
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: Optional[int] = Field(default=None, index=True)
class Hero(HeroBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
class HeroCreate(HeroBase):
pass
class HeroPublic(HeroBase):
id: int
class HeroUpdate(SQLModel):
name: Optional[str] = None
secret_name: Optional[str] = None
age: 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}
from typing import List, Optional
from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select
class HeroBase(SQLModel):
name: str = Field(index=True)
secret_name: str
age: Optional[int] = Field(default=None, index=True)
class Hero(HeroBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
class HeroCreate(HeroBase):
pass
class HeroPublic(HeroBase):
id: int
class HeroUpdate(SQLModel):
name: Optional[str] = None
secret_name: Optional[str] = None
age: 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}
小结¶
你刚刚学习了如何使用 FastAPI 依赖项 来处理数据库会话。这将在稍后的测试代码中派上用场。
随着你在 FastAPI 中的工作越来越多，你会发现这些依赖项能帮助你处理 权限、认证、数据库 会话 等资源。🚀
如果你想了解更多关于依赖项的内容，请查看 FastAPI 文档中的依赖项。