Inner Join Many to Many Tables with Filter In MySQL

Question

table structure ....Here is only 3 tables.. (bought ,customer,product). ..

bought table structure : fields (id,product_id,customer_id), 
customer table struc         


        

Answer 1

I want to get customers who bought product 'a' but did not buy products 'b'

Try this:

SELECT * 
FROM Customers c
INNER JOIN
(
     SELECT * 
     FROM bought 
     WHERE product_id = id of 'a'
) ba ON c.CustomerId = ba.CustomerId
LEFT JOIN
(
     SELECT * 
     FROM bought 
     WHERE product_id = id of 'b'
) bb ON c.CustomerId = bb.CustomerId
WHERE bb.CustomerId IS NULL;