To effectively protect against SQL injection attacks, it is crucial to use parameterized queries or prepared statements. These programming techniques ensure that user input is treated as data and not executable code. For instance, when using libraries like PDO in PHP or ADO.NET in C#, you can bind parameters to the SQL query, thus isolating the code from the data. This not only prevents attackers from injecting malicious SQL code but also improves code readability and maintainability. Always validate and sanitize user input before processing, leveraging built-in functions that help eliminate harmful input patterns.

Additionally, applying the principle of least privilege is essential for securing database connections. Database accounts used by applications should have restricted permissions, limited to only the necessary operations needed for their function, thereby minimizing the impact of a successful injection attack. Keeping your database and application code updated, alongside implementing web application firewalls (WAFs) as a second layer of defense, further fortifies your application against vulnerabilities. Regular security audits and penetration testing are also recommended practices to identify and fix potential weaknesses within your application infrastructure.