日安，我正在使用FastAPI，我想在index.html上呈现数据库内容-但是我得到以下错误：

INFO:     127.0.0.1:55139 - "GET /?skip=0&limit=100 HTTP/1.1" 500 Internal Server Error
ERROR:    Exception in ASGI application
Traceback (most recent call last):
  File "/Users/barnaby/.local/share/virtualenvs/fastapi-example-6xjq_vv2/lib/python3.9/site-packages/uvicorn/protocols/http/h11_impl.py", line 394, in run_asgi
    result = await app(self.scope, self.receive, self.send)
  File "/Users/barnaby/.local/share/virtualenvs/fastapi-example-6xjq_vv2/lib/python3.9/site-packages/uvicorn/middleware/proxy_headers.py", line 45, in __call__
    return await self.app(scope, receive, send)
  File "/Users/barnaby/.local/share/virtualenvs/fastapi-example-6xjq_vv2/lib/python3.9/site-packages/fastapi/applications.py", line 190, in __call__
    await super().__call__(scope, receive, send)
  File "/Users/barnaby/.local/share/virtualenvs/fastapi-example-6xjq_vv2/lib/python3.9/site-packages/starlette/applications.py", line 111, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/Users/barnaby/.local/share/virtualenvs/fastapi-example-6xjq_vv2/lib/python3.9/site-packages/starlette/middleware/errors.py", line 181, in __call__
    raise exc from None
  File "/Users/barnaby/.local/share/virtualenvs/fastapi-example-6xjq_vv2/lib/python3.9/site-packages/starlette/middleware/errors.py", line 159, in __call__
    await self.app(scope, receive, _send)
  File "/Users/barnaby/.local/share/virtualenvs/fastapi-example-6xjq_vv2/lib/python3.9/site-packages/starlette/middleware/cors.py", line 78, in __call__
    await self.app(scope, receive, send)
  File "/Users/barnaby/.local/share/virtualenvs/fastapi-example-6xjq_vv2/lib/python3.9/site-packages/starlette/exceptions.py", line 82, in __call__
    raise exc from None
  File "/Users/barnaby/.local/share/virtualenvs/fastapi-example-6xjq_vv2/lib/python3.9/site-packages/starlette/exceptions.py", line 71, in __call__
    await self.app(scope, receive, sender)
  File "/Users/barnaby/.local/share/virtualenvs/fastapi-example-6xjq_vv2/lib/python3.9/site-packages/starlette/routing.py", line 566, in __call__
    await route.handle(scope, receive, send)
  File "/Users/barnaby/.local/share/virtualenvs/fastapi-example-6xjq_vv2/lib/python3.9/site-packages/starlette/routing.py", line 227, in handle
    await self.app(scope, receive, send)
  File "/Users/barnaby/.local/share/virtualenvs/fastapi-example-6xjq_vv2/lib/python3.9/site-packages/starlette/routing.py", line 41, in app
    response = await func(request)
  File "/Users/barnaby/.local/share/virtualenvs/fastapi-example-6xjq_vv2/lib/python3.9/site-packages/fastapi/routing.py", line 188, in app
    raw_response = await run_endpoint_function(
  File "/Users/barnaby/.local/share/virtualenvs/fastapi-example-6xjq_vv2/lib/python3.9/site-packages/fastapi/routing.py", line 137, in run_endpoint_function
    return await run_in_threadpool(dependant.call, **values)
  File "/Users/barnaby/.local/share/virtualenvs/fastapi-example-6xjq_vv2/lib/python3.9/site-packages/starlette/concurrency.py", line 34, in run_in_threadpool
    return await loop.run_in_executor(None, func, *args)
  File "/usr/local/Cellar/[email protected]/3.9.0_1/Frameworks/Python.framework/Versions/3.9/lib/python3.9/concurrent/futures/thread.py", line 52, in run
    result = self.fn(*self.args, **self.kwargs)
  File "./sql_app/main.py", line 51, in read_notes
    "title": title,
NameError: name 'title' is not defined

Main.py

from fastapi import FastAPI
from typing import List, Dict

from fastapi import Depends, FastAPI, HTTPException, Request, Response
from fastapi.responses import HTMLResponse
from fastapi.middleware.cors import CORSMiddleware
from sqlalchemy.orm import Session
from fastapi.templating import Jinja2Templates

from . import crud, models, schemas
from .database import SessionLocal, engine

models.Base.metadata.create_all(bind=engine)

templates = Jinja2Templates(directory="templates")

app = FastAPI()

app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_methods=["*"],
    allow_headers=["*"],
)

# Dependency
def get_db():
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()

# #original function
# @app.get("/notes", response_model=List[schemas.Note])
# def read_notes(request: Request, skip: int = 0, limit: int = 100, db: Session = Depends(get_db)):
#     notes = crud.get_notes(db=db, skip=skip, limit=limit)
#     print(notes)
#     return notes


@app.get("/", response_class=HTMLResponse)
def read_notes(request: Request, skip: int = 0, limit: int = 100, db: Session = Depends(get_db)):
    notes = crud.get_notes(db=db, skip=skip, limit=limit)
    print(notes)
    return templates.TemplateResponse("index.html",{
        "request": request,
        "id": id,
        "title": title,
        "description": description
    })

@app.post("/notes", response_model=schemas.Note, status_code=201)
def create_note(note: schemas.NoteCreate, db: Session = Depends(get_db)):
    return crud.create_note(db=db, note=note)



@app.get("/notes/{note_id}", response_model=schemas.Note)
def read_user(note_id: int, db: Session = Depends(get_db)):
    db_note = crud.get_note(db=db, note_id=note_id)
    if db_note is None:
        raise HTTPException(status_code=404, detail="Note not found")
    return db_note

@app.delete("/notes/{note_id}", status_code=204)
async def delete_note(note_id: int, db: Session = Depends(get_db)):
    return crud.delete_note(db=db, note_id=note_id)

@app.put("/notes/{note_id}", status_code=200)
async def put_note(note_id: int, note: schemas.NoteCreate, db: Session = Depends(get_db)):
    db_note = schemas.Note(id = note_id, title= note.title, description=note.description)
    crud.update_note(db=db, note=db_note)

@app.patch("/notes/{note_id}", status_code=200)
async def patch_note(note_id: int, note: schemas.NoteCreate, db: Session = Depends(get_db)):
    print(note_id)
    print(note.title)
    print(note.description)
    db_note = schemas.Note(id = note_id, title= note.title, description=note.description)
    crud.update_note(db=db, note=db_note)


if __name__ == '__main__':
    uvicorn.run("main:app", host="127.0.0.1", port=8000)

crud.py

from sqlalchemy.orm import Session

from . import models, schemas

def get_note(db: Session, note_id: int):
    return db.query(models.Note).filter(models.Note.id == note_id).first()

def delete_note(db: Session, note_id: int):
    db_note = db.query(models.Note).filter(models.Note.id == note_id).first()
    db.delete(db_note)
    db.commit()
    return {}

def get_notes(db: Session, skip: int = 0, limit: int = 100):
    return db.query(models.Note).offset(skip).limit(limit).all()

def create_note(db: Session, note: schemas.NoteCreate):
    db_note = models.Note(title=note.title, description=note.description)
    db.add(db_note)
    db.commit()
    db.refresh(db_note)
    return db_note

def update_note(db: Session, note: schemas.Note):
    db_note = db.query(models.Note).filter(models.Note.id == note.id).first()
    db_note.title = note.title
    db_note.description = note.description
    db.commit()
    db.refresh(db_note)
    return db_note

schemas.py

class NoteBase(BaseModel):
    title: str
    description: str

class NoteCreate(NoteBase):
    pass

class Note(NoteBase):
    id: int

    class Config:
        orm_mode = True

models.py

from sqlalchemy import Column, Integer, String
from sqlalchemy.orm import relationship

from .database import Base

class Note(Base):
    __tablename__ = "notes"
    id = Column(Integer, primary_key=True, index=True)
    title = Column(String, nullable=True, default="new")
    description = Column(String, nullable=True, default="new")

index.html

{% extends 'layout.html' %} {% include 'header.html' %} {% block title %} Home {% endblock %} {% block body %}

<div class="container">
    <div class="row">
        <div class="col md-12">
            <div class="jumbotron">
                <table class="table">
                <thead>
                    <tr>
                        <th scope="col">ID</th>
                        <th scope="col">Title</th>
                        <th scope="col">Description</th>
                    </tr>
                </thead>
                <tbody>
                    <tr>
                        {% for note in notes%}
                        <td>{{notes.id}}</td>
                        <td>{{notes.title}}</td>
                        <td>{{notes.description}}</td>
                        </tr>
                        {% endfor %}
                    <tr>
                </tbody>
                </table>
            </div>
        </div>
    </div>
</div>


{% endblock %}

我的模式/模型是否设置不正确？看看这个端点--http://127.0.0.1:8000/notes，我得到了index.html中显示的以下内容。然而，这是列表格式。但不知何故，我无法通过HTML模板呈现它。

[   {     "title": "title 3",     "description": "title 3 description",     "id": 3   },   {     "title": "title 1 updated",     "description": "string",     "id": 1   },   {     "title": "Title updated 2",     "description": "description updated2",     "id": 2   },   {     "title": "Note 4",     "description": "Note 4 description",     "id": 4   } ]

database.py

from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker

SQLALCHEMY_DATABASE_URL = "postgresql://postgres:123456789@localhost/notes"

engine = create_engine (SQLALCHEMY_DATABASE_URL)
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

Base = declarative_base()