使用 FastAPI 更新数据¶
现在让我们看看如何使用 FastAPI 路径操作在数据库中更新数据。
HeroUpdate 模型¶
我们希望客户端能够更新英雄的 name、secret_name 和 age。
但我们不希望他们为了 更新单个字段 而必须再次包含所有数据。
因此，我们需要将所有这些字段都设置为 可选。
由于 HeroBase 中的某些字段是 必需的（没有默认值），我们需要 创建一个新模型。
提示
这是一种情况，使用 独立模型 可能比试图构建一个复杂的模型继承树更有意义。
因为每个字段 实际上都不同（我们只是将默认值设置为 None，但这已经使其不同），所以将它们放在自己的模型中是有意义的。
所以，让我们创建这个新的 HeroUpdate 模型
# Code above omitted 👆
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
# Code below omitted 👇
👀 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)
db_hero.sqlmodel_update(hero_data)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
🤓 其他版本和变体
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)
db_hero.sqlmodel_update(hero_data)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
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)
db_hero.sqlmodel_update(hero_data)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
这与 HeroBase 几乎相同，但所有字段都是可选的，所以我们不能简单地从 HeroBase 继承。
创建更新路径操作¶
现在让我们在 路径操作 中使用此模型来更新英雄。
我们将使用 PATCH HTTP 操作。这用于 部分更新数据，这正是我们正在做的事情。
# Code above omitted 👆
@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)
db_hero.sqlmodel_update(hero_data)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
👀 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)
db_hero.sqlmodel_update(hero_data)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
🤓 其他版本和变体
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)
db_hero.sqlmodel_update(hero_data)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
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)
db_hero.sqlmodel_update(hero_data)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
我们还从 路径参数 中读取 hero_id，以及请求体，一个 HeroUpdate。
读取现有英雄¶
我们使用 要更新 英雄的 ID 获取 hero_id。
因此，我们需要从数据库中读取英雄，使用我们 读取单个英雄 的 相同逻辑，检查它是否存在，如果不存在则可能为客户端引发错误，等等。
# Code above omitted 👆
@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)
db_hero.sqlmodel_update(hero_data)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
👀 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)
db_hero.sqlmodel_update(hero_data)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
🤓 其他版本和变体
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)
db_hero.sqlmodel_update(hero_data)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
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)
db_hero.sqlmodel_update(hero_data)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
获取新数据¶
HeroUpdate 模型的所有字段都带有 默认值，因为它们都有默认值，它们都是可选的，这正是我们想要的。
但这也意味着如果我们只调用 hero.model_dump()，我们将得到一个字典，其中可能有一些或所有这些值都带有它们的默认值，例如
{
"name": None,
"secret_name": None,
"age": None,
}
然后，如果我们在数据库中用这些数据更新英雄，我们就会删除任何现有值，这可能 不是客户端的本意。
但幸运的是，Pydantic 模型（以及 SQLModel 模型）有一个参数可以传递给 .model_dump() 方法：exclude_unset=True。
这告诉 Pydantic 不包含 客户端 未发送 的值。换句话说，它 只 包含客户端 发送 的值。
因此，如果客户端发送了一个没有值的 JSON
{}
那么我们在 Python 中使用 hero.model_dump(exclude_unset=True) 得到的字典将是
{}
但如果客户端发送了一个 JSON，其中包含
{
"name": "Deadpuddle"
}
那么我们在 Python 中使用 hero.model_dump(exclude_unset=True) 得到的字典将是
{
"name": "Deadpuddle"
}
然后我们使用它来获取客户端实际发送的数据
# Code above omitted 👆
@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)
db_hero.sqlmodel_update(hero_data)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
👀 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)
db_hero.sqlmodel_update(hero_data)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
🤓 其他版本和变体
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)
db_hero.sqlmodel_update(hero_data)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
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)
db_hero.sqlmodel_update(hero_data)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
提示
在 SQLModel 0.0.14 之前，该方法名为 hero.dict(exclude_unset=True)，但为了与 Pydantic v2 保持一致，它被重命名为 hero.model_dump(exclude_unset=True)。
在数据库中更新英雄¶
现在我们有了一个 包含客户端发送的数据的字典，我们可以使用方法 db_hero.sqlmodel_update() 来更新对象 db_hero。
# Code above omitted 👆
@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)
db_hero.sqlmodel_update(hero_data)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
👀 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)
db_hero.sqlmodel_update(hero_data)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
🤓 其他版本和变体
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)
db_hero.sqlmodel_update(hero_data)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
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)
db_hero.sqlmodel_update(hero_data)
session.add(db_hero)
session.commit()
session.refresh(db_hero)
return db_hero
提示
方法 db_hero.sqlmodel_update() 在 SQLModel 0.0.16 中添加。🤓
在此之前，您需要手动获取值并使用 setattr() 设置它们。
方法 db_hero.sqlmodel_update() 接受一个带有另一个模型对象或字典的参数。
对于 原始 模型对象（本例中为 db_hero）中的每个字段，它都会检查该字段是否在 参数（本例中为 hero_data）中可用，然后用提供的值更新它。
移除字段¶
这是一个额外的好处。🎁
当获取客户端发送的数据字典时，我们只包含 客户端实际发送的内容。
这听起来很简单，但它有一些额外的细微差别，这些细微差别变成了 很棒的功能。✨
我们 不仅仅是省略 具有 默认值 的数据。
我们 不仅仅是省略 任何为 None 的数据。
这意味着如果数据库中的模型 具有与默认值不同的值，客户端可以 将其重置为与默认值相同的值，甚至 None，我们仍然会 注意到它 并 相应地更新它。🤯🚀
因此，如果客户端想故意删除英雄的 age，他们可以只发送一个 JSON，其中包含
{
"age": null
}
当使用 hero.model_dump(exclude_unset=True) 获取数据时，我们将得到
{
"age": None
}
因此，我们将使用该值并将数据库中的 age 更新为 None，正如客户端所期望的那样。
请注意，这里的 age 是 None，但 我们仍然检测到了它。
此外，name 甚至没有发送，我们也没有 意外地 将其设置为 None 或其他值。我们只是没有触及它，因为客户端没有发送它，所以我们 完全没问题，即使在这些特殊情况下也是如此。✨
这些是 Pydantic 的一些优点，我们可以将其与 SQLModel 一起使用。🎉
回顾¶
在 SQLModel 模型（和 Pydantic 模型）中使用 .model_dump(exclude_unset=True)，我们可以轻松地 正确 更新数据，即使在 边缘情况 下也是如此。😎