w3resource

SQL Exercise: List the employees who are senior to their own manager

SQL employee Database: Exercise-63 with Solution

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

63. From the following table, write a SQL query to find those employees who are senior to their manager. Return complete information about the employees.

Pictorial Presentation:

SQL exercises on employee Database: List the employees who are senior to their own manager

Sample table: employees


Sample Solution:

SELECT *
FROM employees w,
     employees m
WHERE w.manager_id = m.emp_id
  AND w.hire_date < m.hire_date;

Sample Output:

 emp_id | emp_name | job_name | manager_id | hire_date  | salary  | commission | dep_id | emp_id | emp_name | job_name  | manager_id | hire_date  | salary  | commission | dep_id
--------+----------+----------+------------+------------+---------+------------+--------+--------+----------+-----------+------------+------------+---------+------------+--------
  66928 | BLAZE    | MANAGER  |      68319 | 1991-05-01 | 2750.00 |            |   3001 |  68319 | KAYLING  | PRESIDENT |            | 1991-11-18 | 6000.00 |            |   1001
  67832 | CLARE    | MANAGER  |      68319 | 1991-06-09 | 2550.00 |            |   1001 |  68319 | KAYLING  | PRESIDENT |            | 1991-11-18 | 6000.00 |            |   1001
  65646 | JONAS    | MANAGER  |      68319 | 1991-04-02 | 2957.00 |            |   2001 |  68319 | KAYLING  | PRESIDENT |            | 1991-11-18 | 6000.00 |            |   1001
  63679 | SANDRINE | CLERK    |      69062 | 1990-12-18 |  900.00 |            |   2001 |  69062 | FRANK    | ANALYST   |      65646 | 1991-12-03 | 3100.00 |            |   2001
  64989 | ADELYN   | SALESMAN |      66928 | 1991-02-20 | 1700.00 |     400.00 |   3001 |  66928 | BLAZE    | MANAGER   |      68319 | 1991-05-01 | 2750.00 |            |   3001
  65271 | WADE     | SALESMAN |      66928 | 1991-02-22 | 1350.00 |     600.00 |   3001 |  66928 | BLAZE    | MANAGER   |      68319 | 1991-05-01 | 2750.00 |            |   3001
(6 rows)

Explanation:

The said query in SQL that selects all columns from the 'employees' table twice, with different aliases "w" and "m" to find all employees who were hired before their manager.

The query joins the 'employees' table to itself, to create a relationship between the employee and their manager based on the emp_id and manager_id columns, and the hire date comparison then filters the results to only show employees who were hired earlier than their manager using the WHERE clause.

Relational Algebra Expression:

Relational Algebra Expression: List the employees who are senior to their own manager.

Relational Algebra Tree:

Relational Algebra Tree: List the employees who are senior to their own manager.

Practice Online


Sample Database: employee

employee database structure

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

Previous SQL Exercise: Employees location, grade, and experience over 25 years.
Next SQL Exercise: List the employee with their grade for the grade 4.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.



Become a Patron!

Follow us on Facebook and Twitter for latest update.

It will be nice if you may share this link in any developer community or anywhere else, from where other developers may find this content. Thanks.

https://www.w3resource.com/sql-exercises/employee-database-exercise/sql-employee-database-exercise-63.php