SQL Exercise: Employees whose first or last name begins with D

Last update on January 08 2026 12:47:55 (UTC/GMT +8 hours)

36. From the following table, write a SQL query to find the employees whose first or last name begins with 'D'. Return first name, last name.

Sample table: employees

+-------------+-------------+-------------+----------+--------------------+------------+------------+----------+----------------+------------+---------------+
| EMPLOYEE_ID | FIRST_NAME  | LAST_NAME   | EMAIL    | PHONE_NUMBER       | HIRE_DATE  | JOB_ID     | SALARY   | COMMISSION_PCT | MANAGER_ID | DEPARTMENT_ID |
+-------------+-------------+-------------+----------+--------------------+------------+------------+----------+----------------+------------+---------------+
|         100 | Steven      | King        | SKING    | 515.123.4567       | 2003-06-17 | AD_PRES    | 24000.00 |           0.00 |          0 |            90 |
|         101 | Neena       | Kochhar     | NKOCHHAR | 515.123.4568       | 2005-09-21 | AD_VP      | 17000.00 |           0.00 |        100 |            90 |
|         102 | Lex         | De Haan     | LDEHAAN  | 515.123.4569       | 2001-01-13 | AD_VP      | 17000.00 |           0.00 |        100 |            90 |
|         103 | Alexander   | Hunold      | AHUNOLD  | 590.423.4567       | 2006-01-03 | IT_PROG    |  9000.00 |           0.00 |        102 |            60 |
|         104 | Bruce       | Ernst       | BERNST   | 590.423.4568       | 2007-05-21 | IT_PROG    |  6000.00 |           0.00 |        103 |            60 |
|         105 | David       | Austin      | DAUSTIN  | 590.423.4569       | 2005-06-25 | IT_PROG    |  4800.00 |           0.00 |        103 |            60 |
|         106 | Valli       | Pataballa   | VPATABAL | 590.423.4560       | 2006-02-05 | IT_PROG    |  4800.00 |           0.00 |        103 |            60 |
|         107 | Diana       | Lorentz     | DLORENTZ | 590.423.5567       | 2007-02-07 | IT_PROG    |  4200.00 |           0.00 |        103 |            60 |
|         108 | Nancy       | Greenberg   | NGREENBE | 515.124.4569       | 2002-08-17 | FI_MGR     | 12008.00 |           0.00 |        101 |           100 |
|         109 | Daniel      | Faviet      | DFAVIET  | 515.124.4169       | 2002-08-16 | FI_ACCOUNT |  9000.00 |           0.00 |        108 |           100 |
......
|         206 | William     | Gietz       | WGIETZ   | 515.123.8181       | 2002-06-07 | AC_ACCOUNT |  8300.00 |           0.00 |        205 |           110 |
+-------------+-------------+-------------+----------+--------------------+------------+------------+----------+----------------+------------+---------------+

View the table

Sample Solution:

-- Selecting 'first_name' and 'last_name' from the 'employees' table
SELECT first_name, last_name 
-- Specifying the table to retrieve data from ('employees')
FROM employees 
-- Filtering the results to include rows where 'first_name' starts with 'D' or 'last_name' starts with 'D'
WHERE  first_name  LIKE 'D%' 
   OR last_name LIKE 'D%';

Sample Output:

 first_name | last_name
------------+-----------
 Lex        | De Haan
 David      | Austin
 Diana      | Lorentz
 Daniel     | Faviet
 Den        | Raphaely
 Curtis     | Davies
 David      | Bernstein
 Louise     | Doran
 Danielle   | Greene
 David      | Lee
 Julia      | Dellinger
 Jennifer   | Dilly
 Donald     | OConnell
 Douglas    | Grant
(14 rows)

Code Explanation:

The said query in SQL which selects the "first_name" and "last_name" columns from the 'employees' table where the "first_name" column starts with the letter 'D' (specified using the "LIKE" operator with the pattern 'D%') or the "last_name" column starts with the letter 'D' (specified using the "LIKE" operator with the pattern 'D%').

Relational Algebra Expression: