Only good programming practices prevent SQL Injection attacks. A web application firewall is like a band-aid. If you find an SQL Injection vulnerability but you cannot fix it immediately, you may use a WAF to create temporary rules protecting from an attack. You can even export such rules automatically from Acunetix. However, such rules are often circumvented and you must fix your application as soon as possible. Learn more about Acunetix export to web application firewalls.