Is it possible write this query without using cursor

I have already written above logic using c# code but I want to handle it at database query level as optimization.

I am using mysql database The schema of department is

    Department Table
Deptid     DeptName ParentDeptid
1          CEO        -  
2          HR         1
3          IT         1
4          Dev        3
5          QA         3
6          clerk      5

Employee table
Empid    EmpName   deptid
1        E1            1
2        E2            2
3        E3            3
4        E4            4
5        E5            4
6        E6            4
7        E7            5
8        E8            5
9        E9            5
10       E10           6

I need output as if I have selected deptid is 3 I want all descendent of dept 3. It means for dept id 3

deptid  parentdept  count
3       1           1
4       3           3
5       3           3
6       5           1