Make optimization to SQL query with SQL Server Management Studio



Interview Question: Select only Prime numbers from table




Calculate average time from DateTime MySql

Calculating average time from DateTime field in MySql might come in handy in cases like getting the average arrival time, departure time, service sampling etc. In my case, I have a database with records on my arrival to work, and I wanted to calculate time average time that I arrive by the office, and then calculate how much time I spend in traffic, depending on when I leave my home.


Prevent cookie hijacking (session hacking)

First of all, what is “Cookie Hijacking”?

By Wikipedia, it’s an “exploitation of a valid computer session to gain unauthorized access to information or services in a computer system. In particular, it is used to refer to the theft of a magic cookie used to authenticate a user to a remote server”.

Which basically means, gaining access to an information system or a website without logging in, as the user that the cookie (or session) belongs to him.