When working with SQL, it is common to use JOIN clauses to combine data from multiple tables. Sometimes, you may need to retrieve the maximum value from a column in one table while joining it with another table.

In this blog post, we’ll explore how to use the MAX function in SQL along with JOIN clauses to accomplish this task.

Example Scenario

Let’s consider a scenario where you have two tables: orders and customers. The orders table contains information about the orders placed, including the customer ID (customer_id) and the total order amount (order_amount). The customers table contains customer details, including the customer ID (id) and the customer’s name (name).

SQL Query

To find the maximum order amount along with the corresponding customer name, you can use the following SQL query:

SELECT c.name, o.order_amount
FROM orders o
JOIN customers c ON o.customer_id = c.id
WHERE o.order_amount = (
    SELECT MAX(order_amount)
    FROM orders
)

Let’s break down this query step by step:

1. We start by selecting the customer name (c.name) and order amount (o.order_amount) from the orders and customers tables.
2. We use the JOIN clause to join the orders and customers tables based on the customer ID (o.customer_id = c.id).
3. We then add a WHERE clause to filter the results based on the maximum order amount. The subquery (SELECT MAX(order_amount) FROM orders) retrieves the maximum order amount from the orders table.
4. Finally, we execute the query to retrieve the desired result.

Conclusion

In this blog post, we’ve learned how to use the MAX function in SQL to find the maximum value from a column when using JOIN clauses. By combining the power of MAX and JOIN, you can easily retrieve the desired information from multiple tables.

Remember to adapt this query to match the table names and column names in your specific database schema.