how to group by in linq in c# ?

refer below links:-
http://stackoverflow.com/questions/20163822/how-to-write-simple-group-sql-query-to-linq-query-in-c-sharp[^]
http://stackoverflow.com/questions/1796165/linq-group-by-expression-syntax[^]
http://stackoverflow.com/questions/34913/c-sharp-linq-grouping[^]
http://stackoverflow.com/questions/11069876/how-to-use-group-by-in-a-linq-query[^]

Refer:http://stackoverflow.com/questions/4918754/linq-query-group-by[^]
Try this.

Try something Like...

var q = from c in table
   group c by c.Department;

or visit here for an example of group by clause

Suppose You have an EMPLOYEE table and want to sum of salaries as per employee name and have a data context class EmployeeOperationDataContext so create data context class object. This object contains employee data.

EmployeeOperationDataContext employee = new EmployeeOperationDataContext(); 
 var salarySum = from emp in employee.EMPLOYEEs
                 group emp by emp.Name into empg
                 select new { NAME = empg.Key, SALARY = empg.Sum(x => x.SALARY)};