08-01 COUNT

01

Use a sequential column with the COUNT function to count the number of employees 

SELECT COUNT(emp_id)
from employee;

02

Notice super_id will return 8 instead of 9 because David Wallace super_id is null 

SELECT COUNT(super_id)
from employee;

03

Find number of female employees born after 1970 

SELECT *
from employee
WHERE sex = 'F' and birth_date > '1970-01-01';