What should be use with SQL injection attacks against his web server exposed to the public network?

To defend against SQL injection attacks, it is crucial to use prepared statements and parameterized queries, which separate SQL code from user input, preventing malicious data from altering the query structure. Additionally, implementing input validation and sanitization can further reduce the risk by ensuring that only expected data formats are accepted. Regularly updating and patching database management systems, along with employing web application firewalls, can also enhance security against such vulnerabilities. Lastly, conducting security audits and penetration testing can help identify and address potential weaknesses in the system.