I am learning FastAPI.
My code:
main.py
from . import models, schemas
from .database import SessionLocal, engine
models.Base.metadata.create_all(bind=engine)
app = FastAPI()
# Dependency
def get_db():
db = SessionLocal()
try:
yield db
finally:
db.close()
@app.get("/projects/", response_model=list[schemas.ProjectSchema])
def list_project(db: Session = Depends(get_db)):
""" Get all projects"""
projects = db.query(models.Project).all()
print("XXX_ ", projects) # XXX_ [<src.models.Project ...]
return JSONResponse(content={"message": projects})
models.py
from sqlalchemy import Column, Integer, String
from sqlalchemy.orm import relationship
from .database import Base
class Project(Base):
__tablename__ = "projects"
id = Column(Integer, primary_key=True)
name = Column(String, nullable=False, unique=True)
schemas.py
from typing import List, Union
from pydantic import BaseModel
class ProjectSchema(BaseModel):
name: str
class Config:
orm_mode = True
I have an error for GET /projects request:
TypeError: Object of type Project is not JSON serializable
I have read FastAPI TypeError: Object of type ‘ModelMetaclass’ is not JSON serializable.
I checked that response_model=list[schemas.ProjectSchema] is OK.
How to fix the error?
You’re trying to return the JSON data to a Object response and more over you’re trying to feed Object to JSON.
You can try
return projects this will work.
2
It seems that you need change a return schema to meet your format:
from typing import List, Union
from pydantic import BaseModel
class ProjectSchema(BaseModel):
name: str
class Config:
orm_mode = True
class ReturnProjectsSchema(BaseModel):
message: list[schemas.ProjectSchema]
And in the API you can just:
@app.get("/projects/", response_model=list[schemas.ReturnProjectsSchema])
def list_project(db: Session = Depends(get_db)):
""" Get all projects"""
projects = db.query(models.Project).all()
print("XXX_ ", projects) # XXX_ [<src.models.Project ...]
return {"message": projects}
A schema in response model should be same as the data you are trying to return to a method. Also, it is not necessary to use JSONResponse.