log questions

The `@login_required` decorator is used to restrict access to a view so that only authenticated users can access it. When applied to a view function, it redirects unauthenticated users to the login page. It ensures that certain views are only accessible to users who have logged in.

The NOT function reverses the logical value of its argument. For example, =NOT(A1>10) returns TRUE if A1 is not greater than 10, and FALSE if A1 is greater than 10. This function is useful for negating conditions in logical tests.

Key components of a secure login system include strong password policies, encryption for storing passwords, multi-factor authentication (MFA), secure session management, and regular security updates. Password policies should enforce complexity and length requirements, while encryption techniques like hashing with salts should be used to protect stored passwords. MFA adds an additional layer of security. Secure session management involves using secure cookies and session timeouts. Regular updates address vulnerabilities and enhance overall system security.

The CASE statement allows conditional logic in SQL queries, returning values based on specified conditions. It works like an IF statement. For example, `SELECT name, CASE WHEN score >= 60 THEN 'Pass' ELSE 'Fail' END AS result FROM exams;` assigns 'Pass' or 'Fail' based on the score.