Handling Custom Query Parameters in FastAPI with SQLAlchemy for Complex Filters
I've been working on this all day and I've been researching this but I'm stuck on something that should probably be simple. Quick question that's been bugging me - I've looked through the documentation and I'm still confused about I'm stuck on something that should probably be simple. I'm developing a FastAPI application where I need to implement complex filtering on a SQLAlchemy model based on multiple query parameters. My model is quite simple, consisting of a `User` class with fields like `name`, `age`, and `is_active`. I want to allow users to filter by these fields using query parameters. However, I'm struggling with how to build the dynamic query based on the parameters provided. Here's what I've done so far: ```python from fastapi import FastAPI, Query from sqlalchemy.orm import Session from typing import List, Optional from models import User from database import get_db app = FastAPI() @app.get("/users/") async def get_users( db: Session = Depends(get_db), name: Optional[str] = Query(None), age: Optional[int] = Query(None), is_active: Optional[bool] = Query(None) ) -> List[User]: query = db.query(User) if name: query = query.filter(User.name == name) if age: query = query.filter(User.age == age) if is_active is not None: query = query.filter(User.is_active == is_active) return query.all() ``` The scenario arises when I try to filter by `is_active`, the boolean field. If I set `is_active` to `True` in the URL, I get a 422 Unprocessable Entity behavior. This seems to happen because FastAPI is unable to convert the query parameter into a boolean type correctly. I tried using `strtobool` to convert strings to booleans, but it didn't help. I also checked the URL and it correctly looks something like `http://localhost:8000/users/?is_active=true`. I’ve also read about using `bool` converter in FastAPI, but I’m unsure how to apply it effectively with optional parameters. What is the best way to handle this to ensure that boolean values are processed correctly? Any ideas what could be causing this? This is part of a larger service I'm building. Am I missing something obvious? I'm working on a web app that needs to handle this. Has anyone else encountered this? For reference, this is a production mobile app. I'd really appreciate any guidance on this. I'm using Python 3.9 in this project. Any ideas what could be causing this? I recently upgraded to Python latest. I'd love to hear your thoughts on this.