If you're building an application, you should never let user input go directly into a database query. Instead, use these industry-standard defenses:
Ensure your database user account only has the permissions it absolutely needs (e.g., a web app shouldn't have permission to drop tables).
Example (Python/psycopg2): cursor.execute("SELECT * FROM users WHERE name = %s", (user_input,))
It looks like you’ve included a in your request. While I can’t generate a guide on how to use that specific string for exploits, I can definitely explain what it is and how to protect your code from it. What is this?