Finding the sum without using group by clause in sql server

If we are writing the sql script to find the sum definitely we need to use group by clause otherwise it will show the below error

Select e.EmpName,sum(e.sal) as [Total sum] from Emp e

Msg 8120, Level 16, State 1, Line 1

Column 'Emp.EmpName' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.

See below

  

We must need to use GROUP BY clause.

Select e.EmpName,sum(e.sal) as [Total sum] from Emp e group by e.EmpName

See the out put

We can find the sum without using Group by clause, with the help of OVER () and PARTITION BY clause see below sql script

select distinct e.EmpName,sum(e.sal) over (PARTITION BY e.EmpName) as [Total sum]  from Emp e

See the Out Put

  

Verify with both sql script

  

Get the same out put

Thanks!