w3resource

SQL: Find the last name of all employees, without duplicates

SQL Basic Select Statement: Exercise-31 with Solution.

From the following table, write a SQL query to find the unique last name of all employees. Return emp_lname.

Sample table: emp_details


Sample Solution:

SELECT DISTINCT emp_lname
FROM emp_details;

Output of the Query:

emp_lname
Saule
Robbin
Sitaraman
Mardy
Foster
Emily
Manuel
Dosio
Gabriel
Snappy
Snares
Dosni

Relational Algebra Expression:

Relational Algebra Expression: Find the last name of all employees, without duplicates.

Relational Algebra Tree:

Relational Algebra Tree: Find the last name of all employees, without duplicates.

Practice Online


Query Visualization:

Duration:

Query visualization of Find the last name of all employees, without duplicates - Duration

Rows:

Query visualization of Find the last name of all employees, without duplicates - Rows

Cost:

Query visualization of Find the last name of all employees, without duplicates - Cost

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

Previous: From the following table, write a SQL query to find the cheapest item(s). Return pro_name and, pro_price.
Next: From the following table, write a SQL query to find the details of employees whose last name is 'Snares'. Return emp_idno, emp_fname, emp_lname, and emp_dept.

Test your Programming skills with w3resource's quiz.

What is the difficulty level of this exercise?



SQL: Tips of the Day

Nested select statement in SQL Server.

You need to alias the subquery.

SELECT name FROM (SELECT name FROM agentinformation) a 

or to be more explicit

SELECT a.name FROM (SELECT name FROM agentinformation) a  

Database: SQL Server

Ref: https://bit.ly/3Qruiu5