Is DAO responsible for inserting records into 'join' table

Question

For example, if I have two tables: Customer and Product and I need to map customers to products (many-to-many). So I need a third (join) table, which will contain CustomerId and ProductId. Is DAO responsible for inserting records into the third (join) table?

P.S. For now I have CustomerDAO and ProductDAO. Mapping customers to products handled by a service-layer.

Answer 1

Yes, your DAO can implement methods like

• updateProduct(CustomerId)
• updateCustomer(ProductId)
• findCustomerByProduct(productId)
• findProductsByCustomer(customerId)

Answer 2

Yes of course, it is its responsibility. If not DAO, then who will do it instead of it?