Lab 9: Birthdays

Create a web application to keep track of friends’ birthdays.

screenshot of birthdays website

When to Do It

By 2021-12-31T23:59:00-05:00.

Getting Started

Here’s how to download this lab into your own CS50 IDE. Log into CS50 IDE and then, in a terminal window, execute each of the below.

  • Execute cd to ensure that you’re in ~/ (i.e., your home directory, aka ~).
  • Execute wget to download a (compressed) ZIP file with this problem’s distribution.
  • Execute unzip to uncompress that file.
  • Execute rm followed by yes or y to delete that ZIP file.
  • Execute ls. You should see a directory called lab9, which was inside of that ZIP file.
  • Execute cd lab9 to change into that directory.
  • Execute ls. You should see an file, a birthdays.db file, a static directory, and a templates directory.


In, you’ll find the start of a Flask web application. The application has one route (/) that accepts both POST requests (after the if) and GET requests (after the else). Currently, when the / route is requested via GET, the index.html template is rendered. When the / route is requested via POST, the user is redirected back to / via GET.

birthdays.db is a SQLite database with one table, birthdays, that has four columns: id, name, month, and day. There are a few rows already in this table, though ultimately your web application will support the ability to insert rows into this table!

In the static directory is a styles.css file containing the CSS code for this web application. No need to edit this file, though you’re welcome to if you’d like!

In the templates directory is an index.html file that will be rendered when the user views your web application.

Implementation Details

Complete the implementation of a web application to let users store and keep track of birthdays.

  • When the / route is requested via GET, your web application should display, in a table, all of the people in your database along with their birthdays.
    • First, in, add logic in your GET request handling to query the birthdays.db database for all birthdays. Pass all of that data to your index.html template.
    • Then, in index.html, add logic to render each birthday as a row in the table. Each row should have two columns: one column for the person’s name and another column for the person’s birthday.
  • When the / route is requested via POST, your web application should add a new birthday to your database and then re-render the index page.
    • First, in index.html, add an HTML form. The form should let users type in a name, a birthday month, and a birthday day. Be sure the form submits to / (its “action”) with a method of post.
    • Then, in, add logic in your POST request handling to INSERT a new row into the birthdays table based on the data supplied by the user.

Optionally, you may also:

  • Add the ability to delete and/or edit birthday entries.
  • Add any additional features of your choosing!



  • Recall that you can call db.execute to execute SQL queries within
    • If you call db.execute to run a SELECT query, recall that the function will return to you a list of dictionaries, where each dictionary represents one row returned by your query.
  • You’ll likely find it helpful to pass in additional data to render_template() in your index function so that access birthday data inside of your index.html template.
  • Recall that the tr tag can be used to create a table row and the td tag can be used to create a table data cell.
  • Recall that, with Jinja, you can create a for loop inside your index.html file.
  • In, you can obtain the data POSTed by the user’s form submission via request.form.get(field) where field is a string representing the name attribute of an input from your form.
    • For example, if in index.html, you had an <input name="foo" type="text">, you could use request.form.get("foo") in to extract the user’s input.
Not sure how to solve?


No check50 for this lab! But be sure to test your web application by adding some birthdays and ensuring that the data appears in your table as expected.

Run flask run in your terminal while in your lab9 directory to start a web server that serves your Flask application.

How to Submit

Execute the below, logging in with your GitHub username and password when prompted. For security, you’ll see asterisks (*) instead of the actual characters in your password.

submit50 cs50/labs/2021/x/birthdays