和
Sum
函数求和组中所有行的值。如果省略 group by 子句,则对所有行求和。
placeholderCopyselect sum(salary) TotalSalary
from employees;
TotalSalary |
---|
2500 |
placeholderCopyselect DepartmentId, sum(salary) TotalSalary
from employees
group by DepartmentId;
DepartmentID |
TotalSalary |
---|---|
1 |
2000 |
2 |
500 |