1/*Group by clause is used to group a selected set of rows into a set of summary
2rows by the values of one or more column or expression. It is always used in
3Conjunction with one or more aggregate function.*/
4SELECT AGGREGATE_FUNCTION(Column_Name) FROM Table_Name
5/*Group by exmaple*/
6SELECT city, sum(Salary) as TotalSalary FROM tblEmployee GROUP BY City