Problem with Database ”Could not parse rfc1738 URL from string” - flask-sqlalchemy

Question

Error: Could not parse rfc1738 URL from string. I tried everything, I think and I cannot solve it.
app.config['SQLALCHEMY_DATABASE_URI'] = 'C:/dev/FlaskBlog/blog.db'
db = SQLAlchemy(app)
class Blogpost(db.Model):
id = db.Column(db.Integer, primary_key=True)
title = db.Column(db.String(50))
subtitle = db.Column(db.String(50))
author = db.Column(db.String(20))
date_posted = db.Column(db.DateTime)
content = db.Column(db.Text)
Problem appears when I try to post an article.
Here is addpost route:
#app.route('/addpost', methods=['POST'])
def addpost():
if request.method == 'POST':
title = request.form['title']
subtitle = request.form['subtitle']
author = request.form['author']
content = request.form['content']
post = Blogpost(title=title, subtitle=subtitle, author=author, date_posted=datetime.now())
db.session.add(post)
db.session.commit()
return redirect(url_for('index'))
else:
return render_template('index.html')

Answer 1

There are no test files here, so I can not test.
But I have encountered the same error, and my database is SQLite. The following codes work fine for me:
from sqlalchemy import create_engine
# relative path on Linux: with three slashes
e = create_engine('sqlite:///relative/path/to/database.db')
# absolute path on Linux: with four slashes
e = create_engine('sqlite:////absolute/path/to/database.db')
# absolute path on Windows
e = create_engine('sqlite:///C:\\absolute\\path\\to\\database.db')
And in your case, I think you can change app.config['SQLALCHEMY_DATABASE_URI'] = 'C:/dev/FlaskBlog/blog.db' to app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///C:\\dev\\FlaskBlog\\blog.db'.
For detailed documents: SQLAlchemy 1.4 Documentation

Answer 2

The SQLALCHEMY_DATABASE_URI should be a valid db uri, fix that and it should work. I also struggled with the same problem.