Server-side code

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Quick Questions

Shade in the A or B circle for each question.

1. Where does server-side code run?

A On the web server

B In the user's web browser

2. A student submits a login form. Which code checks the typed password against stored data?

A Server-side code

B The HTML form tag on its own

3. Which job is done by server-side code?

A Changing a button colour when the mouse hovers over it

B Querying the database for a user's orders

4. Which statement is true?

A The browser never talks to the database directly; server-side code does it

B The browser sends SQL straight to the database server

5. What does server-side code build after it has processed a request?

A The user's keyboard input

B The response sent back to the client

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
1cursor.execute("SELECT * FROM users")		AServer-side code reading form data sent from the client
2name = request.form["name"]		BDatabase queries are put in browser code, but the browser should never access the database directly; the server-side code must run the query.
3Server-side code builds the response that is sent back to the client		CServer-side code querying the database for stored data
4Server-side code handles a request that arrives from the browser		Dreturn "<h1>Hello " + name + "</h1>"
5<script>db.query("SELECT * FROM users")</script>		EThe function never returns anything, so the server has no response to send back to the client.
6def login(): name = request.form["name"]		F@app.route("/login", methods=["POST"])

Definitions

server-side code

Fill in the Blanks

Complete each line of code by filling in the missing parts.

def login(): name = request.____["name"]

def users(): cur = db.cursor() cur._______("SELECT * FROM users")

def welcome(): return _______________("home.html")

@app.route("/login", methods=["____"]) def login():

def login(): if request.______ == "POST": name = request.form["name"]

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A def handle(request):

B name = request.form("name")

C msg = "Hello, " + name

D return msg

Question 2

A def show_users(db)

B q = "SELECT * FROM users"

C rows = db.execute(q)

D return str(rows)

Question 3

A def get_users(db):

B cur = db.cursor()

C q = "SELECT * FORM users"

D cur.execute(q)

E return cur.fetchall()

Question 4

A def page(name):

B h = "<p>" + name + "<p>"

C return h

Question 5

A def check_age(form):

B age = int(form["age"])

C if age >= "18":

D return "Welcome"

E return "Too young"

Answer Key

Server-side code

Section A: Quick Questions

A — On the web server

A — Server-side code

B — Querying the database for a user's orders

A — The browser never talks to the database directly; server-side code does it

B — The response sent back to the client

Section B: Match the Pairs

cursor.execute("SELECT * FROM users") → Server-side code querying the database for stored data

name = request.form["name"] → Server-side code reading form data sent from the client

Server-side code builds the response that is sent back to the client → return "<h1>Hello " + name + "</h1>"

Server-side code handles a request that arrives from the browser → @app.route("/login", methods=["POST"])

def login(): name = request.form["name"] → The function never returns anything, so the server has no response to send back to the client.

Section C: Definitions

server-side code — Code that runs on the web server, not the browser. It handles a request, processes form data, queries the database and builds the response sent back to the client.

Section D: Fill in the Blanks

def login():
    name = request.form["name"]

def users():
    cur = db.cursor()
    cur.execute("SELECT * FROM users")

def welcome():
    return render_template("home.html")

@app.route("/login", methods=["POST"])
def login():

def login():
    if request.method == "POST":
        name = request.form["name"]

Section E: Spot the Error

B — Submitted form data is read by indexing the form with square brackets, request.form["name"]. The form is not a function, so it cannot be called with round brackets.

A — A function definition must end with a colon. It should be def show_users(db): so the server code can run.

C — The SQL keyword is FROM, not FORM. The database would reject this query, so the server could not get the data. It should be SELECT * FROM users.

B — The closing tag must be </p>. Using <p> again opens a second paragraph, so the HTML response sent to the client is broken.

C — The form value was converted to an integer, so it must be compared with the number 18, not the string "18". Comparing an int with a string causes an error.