SQL Exercises: Find the last name of all employees, without duplicates
From the following table, write a SQL query to find the unique last name of all employees. Return emp_lname.
Sample table: emp_details
EMP_IDNO EMP_FNAME EMP_LNAME EMP_DEPT --------- --------------- --------------- ---------- 127323 Michale Robbin 57 526689 Carlos Snares 63 843795 Enric Dosio 57 328717 Jhon Snares 63 444527 Joseph Dosni 47 659831 Zanifer Emily 47 847674 Kuleswar Sitaraman 57 748681 Henrey Gabriel 47 555935 Alex Manuel 57 539569 George Mardy 27 733843 Mario Saule 63 631548 Alan Snappy 27 839139 Maria Foster 57
Sample Solution:
-- This query selects distinct values from the 'emp_lname' column of the 'emp_details' table.
SELECT DISTINCT emp_lname
-- Specifies the table from which to retrieve the data (in this case, 'emp_details').
FROM emp_details;
Output of the Query:
emp_lname Saule Robbin Sitaraman Mardy Foster Emily Manuel Dosio Gabriel Snappy Snares Dosni
Code Explanation:
The given SQL statement selects the distinct emp_lname (last name) values from the table named 'emp_details'. That is, it returns a list of unique last names of employees without any duplicates.
Relational Algebra Expression:
Relational Algebra Tree:
Practice Online
For more Practice: Solve these Related Problems:
- Write a SQL query to find the unique first names of all employees in the table.
- Write a SQL query to retrieve distinct department IDs from the employee details table.
- Write a SQL query to list all unique combinations of first and last names from the employee table.
- Write a SQL query to identify unique job titles held by employees in the organization.
Have another way to solve this solution? Contribute your code (and comments) through Disqus.
Previous SQL Exercise: Find the name and price of the cheapest item(s).
Next SQL Exercise: Find the data of employees whose last name is 'Snares'.
What is the difficulty level of this exercise?
Test your Programming skills with w3resource's quiz.