Update Data with FastAPI¶
Now let's see how to update data in the database with a FastAPI path operation.
HeroUpdate Model¶
We want clients to be able to update the name, the secret_name, and the age of a hero.
But we don't want them to have to include all the data again just to update a single field.
So, we need to have all those fields marked as optional.
And because the HeroBase has some of them as required and not optional, we will need to create a new model.
Tip
Here is one of those cases where it probably makes sense to use an independent model instead of trying to come up with a complex tree of models inheriting from each other.
Because each field is actually different (we just change it to Optional, but that's already making it different), it makes sense to have them in their own model.
So, let's create this new HeroUpdate model:
# 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 👇
# Code above omitted 👆
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
# Code below omitted 👇
# Code above omitted 👆
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
# Code below omitted 👇
👀 Full file preview
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
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
This is almost the same as HeroBase, but all the fields are optional, so we can't simply inherit from HeroBase.
Create the Update Path Operation¶
Now let's use this model in the path operation to update a hero.
We will use a PATCH HTTP operation. This is used to partially update data, which is what we are doing.
# 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
# Code below omitted 👇
# 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
# Code below omitted 👇
# 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
# Code below omitted 👇
👀 Full file preview
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
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
We also read the hero_id from the path parameter and the request body, a HeroUpdate.
Read the Existing Hero¶
We take a hero_id with the ID of the hero we want to update.
So, we need to read the hero from the database, with the same logic we used to read a single hero, checking if it exists, possibly raising an error for the client if it doesn't exist, etc.
# 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
# Code below omitted 👇
# 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
# Code below omitted 👇
# 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
# Code below omitted 👇
👀 Full file preview
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
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
Get the New Data¶
The HeroUpdate model has all the fields with default values, because they all have defaults, they are all optional, which is what we want.
But that also means that if we just call hero.model_dump() we will get a dictionary that could potentially have several or all of those values with their defaults, for example:
{
"name": None,
"secret_name": None,
"age": None,
}
And then, if we update the hero in the database with this data, we would be removing any existing values, and that's probably not what the client intended.
But fortunately Pydantic models (and so SQLModel models) have a parameter we can pass to the .model_dump() method for that: exclude_unset=True.
This tells Pydantic to not include the values that were not sent by the client. Saying it another way, it would only include the values that were sent by the client.
So, if the client sent a JSON with no values:
{}
Then the dictionary we would get in Python using hero.model_dump(exclude_unset=True) would be:
{}
But if the client sent a JSON with:
{
"name": "Deadpuddle"
}
Then the dictionary we would get in Python using hero.model_dump(exclude_unset=True) would be:
{
"name": "Deadpuddle"
}
Then we use that to get the data that was actually sent by the client:
# 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
# Code below omitted 👇
# 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
# Code below omitted 👇
# 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
# Code below omitted 👇
👀 Full file preview
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
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
Tip
Before SQLModel 0.0.14, the method was called hero.dict(exclude_unset=True), but it was renamed to hero.model_dump(exclude_unset=True) to be consistent with Pydantic v2.
Update the Hero in the Database¶
Now that we have a dictionary with the data sent by the client, we can use the method db_hero.sqlmodel_update() to update the object 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
# Code below omitted 👇
# 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
# Code below omitted 👇
# 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
# Code below omitted 👇
👀 Full file preview
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
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
Tip
The method db_hero.sqlmodel_update() was added in SQLModel 0.0.16. 🤓
Before that, you would need to manually get the values and set them using setattr().
The method db_hero.sqlmodel_update() takes an argument with another model object or a dictionary.
For each of the fields in the original model object (db_hero in this example), it checks if the field is available in the argument (hero_data in this example) and then updates it with the provided value.
Remove Fields¶
Here's a bonus. 🎁
When getting the dictionary of data sent by the client, we only include what the client actually sent.
This sounds simple, but it has some additional nuances that become nice features. ✨
We are not simply omitting the data that has the default values.
And we are not simply omitting anything that is None.
This means that if a model in the database has a value different than the default, the client could reset it to the same value as the default, or even None, and we would still notice it and update it accordingly. 🤯🚀
So, if the client wanted to intentionally remove the age of a hero, they could just send a JSON with:
{
"age": null
}
And when getting the data with hero.model_dump(exclude_unset=True), we would get:
{
"age": None
}
So, we would use that value and update the age to None in the database, just as the client intended.
Notice that age here is None, and we still detected it.
Also, that name was not even sent, and we don't accidentally set it to None or something. We just didn't touch it because the client didn't send it, so we are perfectly fine, even in these corner cases. ✨
These are some of the advantages of Pydantic, that we can use with SQLModel. 🎉
Recap¶
Using .model_dump(exclude_unset=True) in SQLModel models (and Pydantic models) we can easily update data correctly, even in the edge cases. 😎