Why do I get a null row in my sqlite database in flask?-CodePudding

Every time I upload a post, it will post a row with null values inside all of the columns except the date and id, and then add a second row with the correct information put in each column. The SQLite data looks like this. Using SQL-alchemy, flask-login, wtf-forms, flask-bootstrap,werkzeug.

id  title   content posting_user    date_posted
1   null    null    jack          2021-11-01
2   adad    test    jack          2021-11-01

Post Model

class Posts(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String(50))
    content = db.Column(db.Text)
    posting_user = db.Column(db.String(255))
    date_posted = db.Column(db.String(50))

class Postform(FlaskForm):
    title = StringField('Title', validators=[InputRequired(), Length(min = 3, max = 50)])
    content = StringField('Content', validators=[InputRequired()], widget=TextArea())

HTML block

<div class="container">
    <div class="row">
        <div class="col-md-4 offset-md-4">
            <div class="login-form bg-light mt-4 p-4">
                <form action="" method="POST" class="row g-3">
                    <h4>Add a Post</h4>
                    {{ form.hidden_tag()}}
                    {{ form.title(placeholder = "Title") }}
                    {{ form.content(cols="30", rows="15", placeholder = "Write your review here") }}
                    <div class="col-12">
                        <button type="submit" name = "post_submit" class="btn btn-dark float-end">Post</button>
                    </div>
                </form>
            </div>
        </div>
    </div>
</div>

app.py

@app.route('/dashboard/post', methods = ["POST", "GET"])
@login_required
def post():
    form = Postform()
    posting = Posts(title = form.title.data, content = form.content.data, posting_user = current_user.username, date_posted = datetime.datetime.now().date())
    if posting.title != None and posting.content != None:
        db.session.add(posting)
        db.session.commit()
    flash('Your post has been added', 'posted')
    return render_template("post.html", form = form, loggedin = current_user.is_active)

CodePudding user response：

It is possible that you send a GET request before your POST request in which the form is still empty. You can differentiate between the request methods to control the behavior.

@app.route('/dashboard/post', methods = ["POST", "GET"])
@login_required
def post():
    form = Postform()
    # Validate whether the request method is post and the entries are correct! 
    if form.validate_on_submit(): 
        posting = Posts(title = form.title.data, content = form.content.data, posting_user = current_user.username, date_posted = datetime.datetime.now().date())
        db.session.add(posting)
        db.session.commit()
        flash('Your post has been added', 'posted')
    return render_template("post.html", form = form, loggedin = current_user.is_active)