Connect to MSSQL Database using Flask-SQLAlchemy

Question

I\'m trying to connect to a local MSSQL DB through Flask-SQLAlchemy.

Here\'s a code excerpt from my __init__.py file:

from flask import          


        

Answer 1

So I just had a very similar problem and was able to solve by doing the following.

Following the SQL Alchemy documentation I found I could use the my pyodbc connection string like this:

# Python 2.x
import urllib
params = urllib.quote_plus("DRIVER={SQL Server Native Client 10.0};SERVER=dagger;DATABASE=test;UID=user;PWD=password")
engine = create_engine("mssql+pyodbc:///?odbc_connect=%s" % params)

# Python 3.x
import urllib
params = urllib.parse.quote_plus("DRIVER={SQL Server Native Client 10.0};SERVER=dagger;DATABASE=test;UID=user;PWD=password")
engine = create_engine("mssql+pyodbc:///?odbc_connect=%s" % params)


# using the above logic I just did the following
params = urllib.parse.quote_plus('DRIVER={SQL Server};SERVER=HARRISONS-THINK;DATABASE=LendApp;Trusted_Connection=yes;')
app.config['SQLALCHEMY_DATABASE_URI'] = "mssql+pyodbc:///?odbc_connect=%s" % params

This then caused an additional error because I was also using Flask-Migrate and apparently it doesn't like % in the connection URI. So I did some more digging and found this post. I then changed the following line in my ./migrations/env.py file

From:

from flask import current_app
config.set_main_option('sqlalchemy.url',
                   current_app.config.get('SQLALCHEMY_DATABASE_URI'))

To:

from flask import current_app
db_url_escaped = current_app.config.get('SQLALCHEMY_DATABASE_URI').replace('%', '%%')
config.set_main_option('sqlalchemy.url', db_url_escaped)

After doing all this I was able to do my migrations and everything seems as if it is working correctly now.