SQL Injection and Safe Query Construction

SQL injection has been on the OWASP Top 10 for over two decades. It’s one of the oldest web vulnerabilities, yet it still breaks production systems today. Despite modern frameworks, ORMs, and linters, new injection bugs keep showing up. The reason is simple: SQL injection isn’t a database or framework problem. It’s a coding problem. As long as user input is stitched directly into query strings, the risk remains.

This chapter focuses on why injection works, why parameterized queries are the only reliable fix, and how to use them correctly in Python, Java, and Node.js. We’ll also cover common misconceptions like the stored procedure myth, second-order injection, and additional safeguards that reduce the impact of mistakes.