Abstract: Nowadays the most used applications are the web based applications, for instance long range informal communication, shopping, e-learning, banking and social networking are all an examples of ...
-- select all data from the employees table. select * from employees; -- select all data from the departments table. select * from departments; -- select all data ...
--set salary = 0 where salary is null We don't fill null values with mean or middle values because this employees is joined recently and there salary is not updated on data yet.