SQL Aliases — How to Rename Columns and Tables

Column Aliases

A column alias renames a column in the query output. The actual table is not changed:

SELECT Name AS EmployeeName,
       Salary AS MonthlySalary
FROM Employees;

+--------------+---------------+
| EmployeeName | MonthlySalary |
+--------------+---------------+
| Priya K.     | 55000         |
| John D.      | 62000         |
| Arun M.      | 78000         |
| Emma W.      | 51000         |
| Ravi S.      | 72000         |
| Sara L.      | 58000         |
+--------------+---------------+

Aliases with Calculations

Aliases are especially useful for calculated columns that have no natural name. You learned about aggregate functions like SUM and AVG earlier — aliases make their output readable:

SELECT Name,
       Salary * 12 AS AnnualSalary,
       Salary * 12 * 0.10 AS AnnualTax
FROM Employees;

+-----------+--------------+-----------+
| Name      | AnnualSalary | AnnualTax |
+-----------+--------------+-----------+
| Priya K.  | 660000       | 66000     |
| John D.   | 744000       | 74400     |
| Arun M.   | 936000       | 93600     |
+-----------+--------------+-----------+

Aliases with Spaces

If your alias contains spaces, wrap it in quotes or brackets:

SELECT Name AS 'Employee Name',
       City AS 'Work Location'
FROM Employees;

AS Is Optional

The AS keyword is optional in most databases. These two are identical:

SELECT Name AS EmployeeName FROM Employees;
SELECT Name EmployeeName FROM Employees;

Table Aliases

Table aliases give a short name to a table. This is especially useful with JOINs:

SELECT e.Name, e.Department, e.Salary
FROM Employees AS e
WHERE e.Salary > 60000;

+-----------+------------+--------+
| Name      | Department | Salary |
+-----------+------------+--------+
| John D.   | Marketing  | 62000  |
| Arun M.   | IT         | 78000  |
| Ravi S.   | IT         | 72000  |
+-----------+------------+--------+

The table Employees is aliased as e. You can then use e.Name instead of Employees.Name.

Table Aliases with JOINs

Table aliases become essential when joining multiple tables:

SELECT e.Name, d.DepartmentName, e.Salary
FROM Employees AS e
INNER JOIN Departments AS d
  ON e.DeptID = d.ID;

Without aliases, you would need to write Employees.Name and Departments.DepartmentName every time. Aliases save typing and improve readability. You will learn JOINs in detail in the next chapter.

When to Use Aliases

For a complete reference of the SELECT syntax, see the official MySQL SELECT documentation.

If you work with data regularly, explore our ready-made Dashboard Templates on NextGenTemplates that use SQL-powered data for business reporting.

📺 Visit our YouTube channel @NeoTechNavigators for step-by-step video tutorials and dashboard demos on this topic.

SELECT Name AS Employee,
       Department AS Team,
       Salary * 1.15 AS NewSalary
FROM Employees;

📖 Chapter 19 of 30 — SQL Tutorial on Neotech Navigators