UNION combining result sets in SQL - Mini Project: Build & Apply

Combine Customer and Supplier Names Using UNION

📖 Scenario: You work for a company that has two separate tables: one for customers and one for suppliers. Both tables have a column called name that stores the names of people or companies.Your manager wants a single list of all unique names from both tables combined.

🎯 Goal: Create a SQL query that uses UNION to combine the name columns from the customers and suppliers tables into one list without duplicates.

📋 What You'll Learn

Use the customers table with a name column

Use the suppliers table with a name column

Write a SQL query that selects name from both tables

Combine the results using UNION to remove duplicates

Order the final result by name alphabetically

💡 Why This Matters

🌍 Real World

Combining data from different sources to create unified reports or lists is common in business databases.

💼 Career

Knowing how to use UNION helps database professionals merge data cleanly without duplicates, which is essential for accurate reporting.

1

Create the customers table with sample data

Write SQL statements to create a table called customers with a column name of type VARCHAR(50). Insert these exact names into customers: 'Alice', 'Bob', 'Charlie'.

SQL

-- Create customers table and insert data
-- Your code here

Need a hint?

Use CREATE TABLE customers (name VARCHAR(50)); and then INSERT INTO customers (name) VALUES ('Alice'), ('Bob'), ('Charlie');

2

Create the suppliers table with sample data

Write SQL statements to create a table called suppliers with a column name of type VARCHAR(50). Insert these exact names into suppliers: 'Bob', 'Diana', 'Edward'.

SQL

CREATE TABLE customers (name VARCHAR(50));
INSERT INTO customers (name) VALUES ('Alice'), ('Bob'), ('Charlie');
-- Create suppliers table and insert data
-- Your code here

Need a hint?

Use CREATE TABLE suppliers (name VARCHAR(50)); and then INSERT INTO suppliers (name) VALUES ('Bob'), ('Diana'), ('Edward');

3

Write a query to select names from customers

Write a SQL query that selects the name column from the customers table.

SQL

CREATE TABLE customers (name VARCHAR(50));
INSERT INTO customers (name) VALUES ('Alice'), ('Bob'), ('Charlie');
CREATE TABLE suppliers (name VARCHAR(50));
INSERT INTO suppliers (name) VALUES ('Bob'), ('Diana'), ('Edward');
-- Select name from customers
-- Your code here

Need a hint?

Use SELECT name FROM customers; to get the names from customers.

4

Combine names from customers and suppliers using UNION

Write a SQL query that selects the name column from customers and combines it with the name column from suppliers using UNION. Order the combined results by name alphabetically.

SQL

CREATE TABLE customers (name VARCHAR(50));
INSERT INTO customers (name) VALUES ('Alice'), ('Bob'), ('Charlie');
CREATE TABLE suppliers (name VARCHAR(50));
INSERT INTO suppliers (name) VALUES ('Bob'), ('Diana'), ('Edward');
-- Combine names from customers and suppliers using UNION and order by name
-- Your code here

Need a hint?

Use SELECT name FROM customers UNION SELECT name FROM suppliers ORDER BY name; to combine and sort names.