Attempting To Combine These Two SQL Statements Into One

Question

I have been attempting to combine these two SQL statements into one. However, I am having some trouble with it. Here they are:

string sql1 = "SELECT products.product_name 
                FROM products, order_details 
                WHERE products.id=order_details.product_id;";

string sql2 = "SELECT customers.first_name 
                FROM customers, orders 
                WHERE orders.customer_id=customers.id;";

I have been looking at using joins; however, I am getting confused on how to implement the WHERE statements.

Answer 1

Use ANSI JOIN, then it's easy to see how to do multiple joins by relating each table in the sequence to another table.

SELECT c.first_name, p.product_name
FROM customers AS c
JOIN orders AS o ON c.id = o.customer_id
JOIN order_details AS od ON o.id = od.order_id
JOIN products AS p ON p.id = od.product_id