w3resource

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

SQL SORTING and FILTERING on HR Database: Exercise-36 with Solution

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


Sample Solution:

SELECT first_name, last_name 
	FROM employees 
		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:

Relational Algebra Expression: Display all those employees whose first name or last name starts with the letter D.

Relational Algebra Tree:

Relational Algebra Tree: Display all those employees whose first name or last name starts with the letter D.

Practice Online


HR database model

Query Visualization:

Duration:

Query visualization of Display all those employees whose first name or last name starts with the letter D - Duration

Rows:

Query visualization of Display all those employees whose first name or last name starts with the letter D - Rows

Cost:

Query visualization of Display all those employees whose first name or last name starts with the letter D - Cost

Contribute your code and comments through Disqus.

Previous SQL Exercise: Salary ranges for jobs with a minimum and maximum.
Next SQL Exercise: Display jobs with minimum salaries over 9000.

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

Difference between natural join and inner join

One significant difference between INNER JOIN and NATURAL JOIN is the number of columns returned-

Consider:

TableA                           TableB
+------------+----------+        +--------------------+    
|Column1     | Column2  |        |Column1  |  Column3 |
+-----------------------+        +--------------------+
| 1          |  2       |        | 1       |   3      |
+------------+----------+        +---------+----------+

The INNER JOIN of TableA and TableB on Column1 will return

SELECT * FROM TableA AS a INNER JOIN TableB AS b USING (Column1);
SELECT * FROM TableA AS a INNER JOIN TableB AS b ON a.Column1 = b.Column1;
+------------+-----------+---------------------+    
| a.Column1  | a.Column2 | b.Column1| b.Column3|
+------------------------+---------------------+
| 1          |  2        | 1        |   3      |
+------------+-----------+----------+----------+

The NATURAL JOIN of TableA and TableB on Column1 will return:

SELECT * FROM TableA NATURAL JOIN TableB
+------------+----------+----------+    
|Column1     | Column2  | Column3  |
+-----------------------+----------+
| 1          |  2       |   3      |
+------------+----------+----------+

Ref: https://bit.ly/3AG5CId

 





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