SQL exercises on employee Database: Display the department name, grade, no. of employees where at least two employees are working as a SALESMAN

SQL employee Database: Exercise-100 with Solution

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100. From the following table, write a SQL query to find those departments where at least two employees work as a SALESMAN in each grade. Return department name, grade and number of employees.

Sample table: employees

Sample table: department

Sample table: salary_grade

Sample Solution:

SELECT d.dep_name,
       s.grade,
       count(*)
FROM employees e,
     department d,
     salary_grade s
WHERE e.dep_id = d.dep_id
  AND e.job_name = 'SALESMAN'
  AND e.salary BETWEEN s.min_sal AND s.max_sal
GROUP BY d.dep_name,
         s.grade
HAVING count(*) >= 2;

Sample Output:

 dep_name  | grade | count
-----------+-------+-------
 MARKETING |     2 |     2
 MARKETING |     3 |     2
(2 rows)

Relational Algebra Expression:

Relational Algebra Tree:

Practice Online

Sample Database: employee

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