SQL exercises on employee Database: List the name of departments where atleast 2 employees are working in that department

SQL employee Database: Exercise-102 with Solution

[An editor is available at the bottom of the page to write and execute the scripts.]

102. From the following tables, write a SQL query to find those departments where at least two employees work. Return department name, number of employees.

Sample table: employees

Sample table: department

Sample Solution:

SELECT d.dep_name,
       count(*)
FROM employees e,
     department d
WHERE e.dep_id = d.dep_id
GROUP BY d.dep_name
HAVING count(*) >= 2;

Sample Output:

 dep_name  | count
-----------+-------
 FINANCE   |     3
 MARKETING |     6
 AUDIT     |     5
(3 rows)s

Relational Algebra Expression:

Relational Algebra Tree:

Practice Online

Sample Database: employee

Have another way to solve this solution? Contribute your code (and comments) through Disqus.

Previous: From the following table, write a SQL query to find those departments where less than four employees work. Return department ID, number of employees.
Next: From the following table, write a SQL query to check whether the employees ID are unique or not. Return employee id, number of employees.