How do you alias a table and a column in a SELECT?

• A. SELECT e.name AS employee_name FROM employees e
• B. SELECT name AS employee_name FROM employees
• C. SELECT employees AS e.name
• D. SELECT e.name employee_name FROM employees

Answer: (A)

Aliasing lets you rename a table and a column in a SELECT for readability and brevity. To alias a table, put the alias after the table name in the FROM clause: from employees e creates a shorthand e you can use to qualify columns. To alias the output column, use a name after AS: e.name AS employee_name. Combined, SELECT e.name AS employee_name FROM employees e retrieves the name from the employees table and presents it under the header employee_name thanks to the column alias. This shows both kinds of aliasing in one statement. The other patterns either don’t define a table alias, try to alias the table with an invalid target, or misuse the aliasing syntax, so they won’t work in standard SQL. If your dialect allows it, you can also drop AS for a shorter form, e.g., SELECT e.name employee_name FROM employees e.