创建数据库后出现未知数据库错误（sqlalchemy）

Question

I'm getting the next error while trying to run my Flask app:

sqlalchemy.exc.OperationalError
OperationalError: (_mysql_exceptions.OperationalError) (1049, "Unknown database '/home/gerardo/Documentos/python_web_dev/flask-intro/app2.db'")

so it seems like there is no database.. but I ran the next scripts using sqlalchemy_utils and everything was ok:

engine = create_engine("mysql://root:@localhost/home/gerardo/Documentos/python_web_dev/flask-intro/app2.db")

create_database(engine.url)

but still I get the error..

Answer 1

You have confused MySQL, a database server, with SQLite, a database in a file. You created a SQLite file, but are trying to tell MySQL to connect to it, which makes no sense.

Use the sqlite dialect in the connection string.

You can avoid typing the whole path (and tying the app to that path) by pointing to the file relative to the app's location.

import os
db_path = os.path.realpath(os.path.join(os.path.dirname(__file__), 'app2.db'))
engine = create_engine('sqlite://{}'.format(db_path))

Consider using Flask-SQLAlchemy rather than trying to manage the database yourself.