sqlalchemy.exc.OperationalError: (sqlite3.OperationalError) unable to open database file

Question

I'm trying to make a RESTful blog.

The problem occurs when I add a "new post" to my blog, which returns the error below.

I've already tried to google the problem for hours now and can't find any solution.

The code can read data from the database, all of my routes works perfectly fine except the create_new_post route which supposed to add the data.

I've narrowed down on the problems which seems to be the pathing of database, but I can't seem to figure out what's wrong with it.

sqlalchemy.exc.OperationalError: (sqlite3.OperationalError) unable to open database file [SQL: INSERT INTO blog_post (title, subtitle, date, body, author, img_url) VALUES (?, ?, ?, ?, ?, ?)] [parameters: ('Blog Post Title', 'Subtitle goes here', 'August 18, 2021', '<p>BLog Content content</p>\r\n', 'Your Name', 'https://images.unsplash.com/photo-1629103257407-6eee51452cbd?ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&ixlib=rb-1.2.1&auto=format&fit=crop&w=701&q=80')] (Background on this error at: http://sqlalche.me/e/13/e3q8)

from flask import Flask, render_template, redirect, url_for
from flask_bootstrap import Bootstrap
from flask_sqlalchemy import SQLAlchemy
from flask_wtf import FlaskForm
from wtforms import StringField, SubmitField
from wtforms.validators import DataRequired, URL
from flask_ckeditor import CKEditor, CKEditorField
from datetime import datetime, date

app = Flask(__name__)


##CONNECT TO DB
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///posts.db'
db = SQLAlchemy(app)

app.config['SECRET_KEY'] = '8BYkEfBA6O6donzWlSihBXox7C0sKR6b'
ckeditor = CKEditor(app)
Bootstrap(app)

# Returns the current year to be passed on the jinja templates. Used in website's footer
@app.context_processor
def inject_now():
    return {"now": datetime.utcnow()}


##CONFIGURE TABLE
class BlogPost(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String(250), unique=True, nullable=False)
    subtitle = db.Column(db.String(250), nullable=False)
    date = db.Column(db.String(250), nullable=False)
    body = db.Column(db.Text, nullable=False)
    author = db.Column(db.String(250), nullable=False)
    img_url = db.Column(db.String(250), nullable=False)

    


##WTForm
class CreatePostForm(FlaskForm):
    title = StringField("Blog Post Title", validators=[DataRequired()])
    subtitle = StringField("Subtitle", validators=[DataRequired()])
    author = StringField("Your Name", validators=[DataRequired()])
    img_url = StringField("Blog Image URL", validators=[DataRequired(), URL()])
    body = CKEditorField("Blog Content", validators=[DataRequired()])
    submit = SubmitField("Submit Post")


##CKEditor


@app.route('/')
@app.route('/index')
def get_all_posts():
    posts = BlogPost.query.all()
    return render_template("index.html", all_posts=posts)


@app.route("/post/<int:post_id>")
def show_post(post_id):
    requested_post = BlogPost.query.get(post_id)
    return render_template("post.html", post=requested_post)


@app.route("/about")
def about():
    return render_template("about.html")


@app.route("/contact")
def contact():
    return render_template("contact.html")


@app.route("/new-post", methods=["GET", "POST"])
def create_new_post():
    form = CreatePostForm()
    if form.validate_on_submit():
        new_post = BlogPost(
            title=form.title.data,
            subtitle=form.subtitle.data,
            body=form.body.data,
            img_url=form.img_url.data,
            author=form.author.data,
            date=date.today().strftime("%B %d, %Y")
        )
        db.session.add(new_post)
        db.session.commit()
        return redirect(url_for("get_all_posts"))
    return render_template("make-post.html", form=form)


if __name__ == "__main__":
    app.run(debug=True)

Answer 1

please try to put the exact path to the database. you can do this;

import os
basedir = os.path.abspath(os.path.dirname(__file__))
app.config['SQLALCHEMY_DATABASE_URI']="sqlite:///"+os.path.join(basedir, "posts.db")

As for the above example, creates the database posts.db into to the current working directory folder if it does not exist and also creates a connection with the flask server.

For more info please refer here