I have a currently functioning e-commerce site under mySQL.
I want to add a 'wishlist' functionality, and I am attempting to figure out the best way to do so.
I currently have one table for products (each product), and another for inventory (each SKU since some products have multiple SKUs).
I have created in a separate database a way for users to register with the table users.
I want to have a way to allow people to place specific SKUs into a wishlist.
I have had two tables joined together before (product and category for example with a product_category table)... but I am having problems with this one since I have to have three tables joined together (inventory, wishlist, and users).
How do I accomplish this? Database structure gives me so many headaches... thank you for any help you can provide, and I hope my issue is clear.
Using multiple SKUs for the same product may cause problems. Consider using a base product and then use attributes to cover options for a product and generate the sku.
In any case your product page should function the same when a product is added to the cart or when a product is added to the wishlist. In other words treat the wishlist as a secondary cart. A secondary storage similar to the cart storage should do.
I am not sure how you involved the categories tables with the products and wishlists. I don't think you need it.