w3resource

SQL Exercise: List the employees who are either CLERK or MANAGER

SQL employee Database: Exercise-40 with Solution

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

40. From the following table, write a SQL query to find those employees who are either CLERK or MANAGER. Return complete information about the employees.

Sample table: employees


Pictorial Presentation:

SQL exercises on employee Database: List the employees who are either CLERK or MANAGER

Sample Solution:

SELECT *
FROM employees
WHERE job_name IN ('CLERK','MANAGER');

Sample Output:

 emp_id | emp_name | job_name | manager_id | hire_date  | salary  | commission | dep_id
--------+----------+----------+------------+------------+---------+------------+--------
  66928 | BLAZE    | MANAGER  |      68319 | 1991-05-01 | 2750.00 |            |   3001
  67832 | CLARE    | MANAGER  |      68319 | 1991-06-09 | 2550.00 |            |   1001
  65646 | JONAS    | MANAGER  |      68319 | 1991-04-02 | 2957.00 |            |   2001
  63679 | SANDRINE | CLERK    |      69062 | 1990-12-18 |  900.00 |            |   2001
  68736 | ADNRES   | CLERK    |      67858 | 1997-05-23 | 1200.00 |            |   2001
  69000 | JULIUS   | CLERK    |      66928 | 1991-12-03 | 1050.00 |            |   3001
  69324 | MARKER   | CLERK    |      67832 | 1992-01-23 | 1400.00 |            |   1001
(7 rows)

Explanation:

The said query in SQL that retrieves all columns from the 'employees' table.

The WHERE clause includes rows that the "job_name" column must be equal to either 'CLERK' or 'MANAGER'.

Relational Algebra Expression:

Relational Algebra Expression: List the employees who are either CLERK or MANAGER.

Relational Algebra Tree:

Relational Algebra Tree: List the employees who are either CLERK or 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: List ID, name, salary, and job_name of the employees.
Next SQL Exercise: All employees except those who joined in February.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.



Follow us on Facebook and Twitter for latest update.

SQL: Tips of the Day

Grouped LIMIT in PostgreSQL: Show the first N rows for each group?

db=# SELECT * FROM xxx;
 id | section_id | name
----+------------+------
  1 |          1 | A
  2 |          1 | B
  3 |          1 | C
  4 |          1 | D
  5 |          2 | E
  6 |          2 | F
  7 |          3 | G
  8 |          2 | H
(8 rows)

I need the first 2 rows (ordered by name) for each section_id, i.e. a result similar to:

id | section_id | name
----+------------+------
  1 |          1 | A
  2 |          1 | B
  5 |          2 | E
  6 |          2 | F
  7 |          3 | G
(5 rows)

PostgreSQL v9.3 you can do a lateral join

select distinct t_outer.section_id, t_top.id, t_top.name from t t_outer
join lateral (
    select * from t t_inner
    where t_inner.section_id = t_outer.section_id
    order by t_inner.name
    limit 2
) t_top on true
order by t_outer.section_id;

Database: PostgreSQL

Ref: https://bit.ly/3AfYwZI

 

We are closing our Disqus commenting system for some maintenanace issues. You may write to us at reach[at]yahoo[dot]com or visit us at Facebook