Unable to insert values into SQLite using Flask and SQLAlchemy

I am using SQLAlchemy along with Flask. I have a sign-up page(which I have named as login by mistake). I have used WTForms to create the sign-up page. If I submit details on the sign-up page, the details should get inserted into SQLite DB that I have created. When I execute my app, I dont get any error message. Everything seems fine, but by the end I dont find my entries in SQLite table.

The following is my login view:

@app.route('/login', methods=['GET', 'POST'])
def login():
    form = LoginForm()
    if form.validate_on_submit():
        t_name=form.Name.data
        t_username=form.UserName.data
        t_email=form.Email.data
        t_password=form.Password.data
        u = User(name=t_name,username=t_username,email=t_email,password=t_password)
        db.session.add(u)
        db.session.commit()
    return render_template('login.html',form=form)

All fields in my Model(Users) are correct without typos.

The following is my login page template

{% extends "base.html" %}

{% block content %}
    <h1>Sign Up</h1>
    <form action="" method="post" name="login">
        <p>
            Name{{ form.Name(size=40) }}
            {% for error in form.Name.errors %}
                <span style="color: red;">[{{ error }}]</span>
            {% endfor %}<br>
        </p>
        <p>
            Username{{ form.UserName(size=40) }}
            {% for error in form.UserName.errors %}
                <span style="color: red;">[{{ error }}]</span>
            {% endfor %}<br>
        </p>
        <p>
            Email{{ form.Email(size=40) }}
            {% for error in form.Email.errors %}
                <span style="color: red;">[{{ error }}]</span>
            {% endfor %}<br>
        </p>
        <p>
            Password{{ form.Password(size=40) }}
            {% for error in form.Password.errors %}
                <span style="color: red;">[{{ error }}]</span>
            {% endfor %}<br>
        </p>
        <p>
            Confirm Password{{ form.ConfirmPassword(size=40) }}
            {% for error in form.ConfirmPassword.errors %}
                <span style="color: red;">[{{ error }}]</span>
            {% endfor %}<br>
        </p>

        <p><input type="submit" value="Submit"></p>
    </form>
{% endblock %}

Can anyone tell me what could be the possible mistake that I've done?