Practice SQL SELECT Interview Questions

Q: Fetch customer names and email addresses

Write and run the SQL query in the interactive editor above to check your answer.

Q: Get all columns from the orders table

Write and run the SQL query in the interactive editor above to check your answer.

Q: Show product name and price with 18% tax applied

Write and run the SQL query in the interactive editor above to check your answer.

Q: List order ID and customer ID with aliases

Write and run the SQL query in the interactive editor above to check your answer.

Q: Retrieve product ID, name, category, and price

Write and run the SQL query in the interactive editor above to check your answer.

Q: Calculate discounted order value at 10% off okay

Write and run the SQL query in the interactive editor above to check your answer.

Q: List customers with their city and country

Write and run the SQL query in the interactive editor above to check your answer.

Q: Fetch item-level detail from order items

Write and run the SQL query in the interactive editor above to check your answer.

The SELECT statement defines what the database returns — which columns, in what form, under what name. It is the first thing every interviewer tests, and where most candidates lose points through imprecision: wrong column names, unnecessary wildcards, missing aliases.

A strong SELECT answer is explicit, clean, and returns exactly what was asked and nothing more.

Syntax

SELECT column1, column2
FROM table_name;

-- With alias
SELECT column1 AS label, expression AS label
FROM table_name;

-- All columns (avoid in interviews unless specifically asked)
SELECT *
FROM table_name;

Key points:

Name columns explicitly in interviews. SELECT * is acceptable only when the question asks for all columns
AS renames the output column. Useful with expressions, aggregates, and long column names
Expressions in SELECT are evaluated before results are returned. Arithmetic, string operations, and functions are all valid here
SELECT without FROM is valid SQL. Useful for evaluating expressions or constants

Example — run it and see

SELECT 
    product_id,
    name,
    price,
    price * 1.18 AS price_with_tax
FROM products
ORDER BY price DESC
LIMIT 5;

Practice Questions

Fetch customer names and email addresses

💡 Three columns from customers. No filter, no alias needed.

SOLUTION

SELECT first_name, last_name, email FROM customers

Get all columns from the orders table

💡 Use the wildcard * to return every column without naming them individually.

SOLUTION

SELECT * FROM orders

Show product name and price with 18% tax applied

💡 Multiply price by 1.18 inside the SELECT clause and alias the result as price_with_tax.

SOLUTION

SELECT name, price * 1.18 AS price_with_tax FROM products

List order ID and customer ID with aliases

💡 Use AS after each column to assign the alias. Two columns, two aliases.

SOLUTION

SELECT order_id AS id, customer_id AS customer FROM orders

Retrieve product ID, name, category, and price

SOLUTION

SELECT product_id, name, category, price FROM products

Calculate discounted order value at 10% off okay

💡 Multiply total_amount by 0.9 and alias it. Include the original total_amount as well.

SOLUTION

SELECT order_id, total_amount, total_amount * 0.9 AS discounted_amount FROM orders

List customers with their city and country

💡 Four columns from customers. No condition or ordering needed.

SOLUTION

SELECT first_name, last_name, city, country FROM customers

Q10

Fetch item-level detail from order items

💡 Five columns from order_items. List them in the exact order given.

SOLUTION

SELECT order_item_id, order_id, product_id, quantity, unit_price FROM order_items