Python Flask: How do you loop over items in a database with SQLAlchemy?

[pc510]

Hi,
I am trying to loop over database entries for books and display them on an e-commerce page.

The books are stored in an SQLAlchemy database with information on title, author, and price.

I want to loop through the database and display the information for each book object in the database along with a picture of the book cover. However, I am not sure how to display this information correctly.

Here is the HTML code

{% block body %}
<h1>Welcome {{ name }}</h1>

<br>
<table style="width:100%">
    <thead>
    <tr>
        <th colspan=3 class="text-center">BOOKS FOR SALE</th>
    </tr>


    <tr>
        {% for book in books %}
        <th class="text-center">{{ books.title }}</th>
        <th class="text-center">{{ books.author }}</th>
        <th class="text-center">{{ books.price }}</th>
        {% endfor %}
    </tr>
    </thead>
    <tbody>
    <tr>
        <td class="text-center"><img class="img-responsive" src="static/book1.jpg"/></td>
        <td class="text-center"><img class="img-responsive" src="static/book2.jpg"/></td>
        <td class="text-center"><img class="img-responsive" src="static/book3.jpg"/></td>
    </tr>

    </tbody>
</table>


{% endblock %}

And here is the books route leading to the page

@app.route('/books')
@login_required
def books_page():
    books = Books.query.all()
    return render_template('bookstest.html', name=current_user.username, books=books)

 

[menator01]

Have a look at this loop

{% for book in books %}
        <th class="text-center">{{ books.title }}</th>
        <th class="text-center">{{ books.author }}</th>
        <th class="text-center">{{ books.price }}</th>
        {% endfor %}

should be

{% for book in books %}
        <th class="text-center">{{ book.title }}</th>
        <th class="text-center">{{ book.author }}</th>
        <th class="text-center">{{ book.price }}</th>
        {% endfor %}

 

[pc510]

Ah, so it needs to be book.title rather than books.title. In other words, whatever you refer to the items as in the loop. Perfect. Thank you! I am still having some HTML issues, but I think it's just a matter of playing with the syntax now.

 

[Deleted member 2829]

Have a look at this loop

{% for book in books %}
        <th class="text-center">{{ books.title }}</th>
        <th class="text-center">{{ books.author }}</th>
        <th class="text-center">{{ books.price }}</th>
        {% endfor %}

should be

{% for book in books %}
        <th class="text-center">{{ book.title }}</th>
        <th class="text-center">{{ book.author }}</th>
        <th class="text-center">{{ book.price }}</th>
        {% endfor %}

Well spotted ! But since when does HTML have loops then, or is this Python as the tag suggests ? Confused....

 

[menator01]

Think it's jinjix or something like that. Been awhile since I've messed with flask

 

[pc510]

Precisely. This is jinja syntax used with the flask module. The {% for a in b %} is how to loop over python lists in Jinja.