Example
Sum function sum the value of all the rows in the group. If the group by clause is omitted then sums all the rows.
select sum(salary) TotalSalary
from employees;
| TotalSalary |
|---|
| 2500 |
select DepartmentId, sum(salary) TotalSalary
from employees
group by DepartmentId;
| DepartmentId | TotalSalary |
|---|---|
| 1 | 2000 |
| 2 | 500 |
