6.3 — Multi-Table Joins

What You'll Learn

• How to join three or more tables in SQL
• How this compares to using multiple VLOOKUPs in Excel
• Syntax and best practices

Sample Tables

Table sales:

SaleID	ProductID	CustomerID	Amount
1	101	1001	120
2	102	1002	80
3	103	1003	50

Table products:

ProductID	ProductName
101	Apples
102	Oranges
103	Bananas

Table customers:

CustomerID	CustomerName
1001	John Smith
1002	Jane Doe
1003	Mike Johnson

Joining Multiple Tables

In Excel, you might use several VLOOKUPs to bring in data from different sheets. In SQL, you can join as many tables as you need.

Example: Join sales, products, and customers

SELECT s.SaleID, s.Amount, p.ProductName, c.CustomerName
FROM sales s
INNER JOIN products p
  ON s.ProductID = p.ProductID
INNER JOIN customers c
  ON s.CustomerID = c.CustomerID;

• Each JOIN adds another table to your results.
• Use table aliases (s, p, c) for readability.

Key Points

• You can join as many tables as needed, as long as you define the relationships.
• Use clear aliases to keep queries readable.

Next Steps

Next, you’ll learn how to migrate your Excel workflows to SQL for more efficient, scalable analysis.