Can't connect PostgreSQL database to FastAPI

Question

So, hi. Everything works with SQLite, but when I try to add PostgreSQL according to the user's guide on FastAPI, nothing works and I get:

sqlalchemy.exc.ProgrammingError: (psycopg2.ProgrammingError) invalid dsn: invalid connection option "check_same_thread"

My database.py is:

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

#SQLALCHEMY_DATABASE_URL = "sqlite:///./sql_app.db"
SQLALCHEMY_DATABASE_URL = "postgresql://user:password@postgresserver/db"

engine = create_engine(
    SQLALCHEMY_DATABASE_URL, connect_args={"check_same_thread": False}
)
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

Base = declarative_base()

Answer 1

check_same_thread is an argument specific to sqlite. As you've specified a Postgres URL, you can remove that argument and you should have no issue creating an engine.

i.e:

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

SQLALCHEMY_DATABASE_URL = "postgresql://user:password@postgresserver/db"

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

Base = declarative_base()