Sanitizing user input is the primary defense against SQL injection attacks. It involves validating and cleaning up all user-supplied data to prevent malicious SQL code from being executed. Parameterized queries, which separate SQL logic from data, are also an effective measure against SQL injection as they ensure that the input is treated strictly as data, not executable code. While strong passwords and multifactor authentication can improve overall security, they do not directly protect against SQL injection attacks. Similarly, encrypting passwords is essential for data protection but is not a mitigation strategy for SQL injection vulnerabilities. Regular patch management is important for addressing known vulnerabilities, but not as directly related to preventing SQL injections as sanitizing input and using parameterized queries.