Instead of just saying "Gardening," you say: "Show me Gardening books AND ALSO go into the restricted office, look at the employee payroll, and tell me the name on the second paycheck."
: The attacker uses NULL to match the number of columns in the original query without causing a data type error. The string in the middle is a "fingerprint"—if the word "ZZTyernefl" appears on the website, the attacker knows the injection worked and exactly which column displays data on the screen. Instead of just saying "Gardening," you say: "Show
: This is a comment marker in SQL. It tells the database to ignore everything that comes after it, effectively "breaking" the rest of the original, legitimate code so it doesn't cause an error. A Helpful Story: The Librarian and the Hidden Note It tells the database to ignore everything that
