Deleting a previously used product catagory warning

I created a duplicate category so I move the 3 items I had in it to the new category with lots of items in it. Whe I tried to delet the now empty old category I get this message:

Are you sure you want to delete this category?

Warning: Linked Products whose Master Categories ID are deleted will not price properly. You should first assure that when deleting a Category that contains Linked Products that you reset the Product(s) Master Categories ID to another Category before removing a Category

First of all, the category is empty, so maybe this is a moot point, and nothing to worry about, but I can't find "master category ID" anywhere to reset. Do I need to change something on those 3 items (somewhere I can't find)before I delete this now empty duplicate category?

Master Categroy ID is within the Product Table, and is a parent reference for all products. The actual product listing for each category is built using the product to categories table, so if this table has no reference in it for that categroy, then the category listing is empty, however, the products may still have the category as their parent. Does that make any sense????

So, to update the parent category, just edit the product as normal, and at the very top of the edit screen, you will see the Master Category ID. This is normally a dropdown if the product is linked. Ensure the new category is selected, and tehn update your product.

As with everything database related, BACKUP your data regularly!

Absolute

Absolute:

Master Categroy ID is within the Product Table, and is a parent reference for all products. The actual product listing for each category is built using the product to categories table, so if this table has no reference in it for that categroy, then the category listing is empty, however, the products may still have the category as their parent. Does that make any sense????

So, to update the parent category, just edit the product as normal, and at the very top of the edit screen, you will see the Master Category ID. This is normally a dropdown if the product is linked. Ensure the new category is selected, and tehn update your product.

As with everything database related, BACKUP your data regularly!

Absolute

No drop down that you speak of in the product edit screen - just the master category itself ID6 listed - so not linked? Again the category is empty, with the products in another category with the exact same name(I made it a sub category now), so can I delete the empty one despite the warning?

I haven't tried editing the product as normal to see what the master category is.

To check the master category for my (mistakenly) linked products, I checked the categories table in PHPMyAdmin. I found that the master_category was zero and the category was null in the table.

Since there was no master category, I felt safe using the red-white x to delete the product. The editing sidebox gave me a choice of which of the two links to delete. That worked well. The verbiage was confusing, but seemed to indicate that whichever one was deleted, the other would become the master.

Since I had ascertained there was no master category in PHPMyAdmin, I went ahead and deleted the product from the unwanted category.

I probably could then have just deleted the main category, but safer deleting unwanted empty subcategories first.

Warning: This deletion process worked so well I actually ended up deleting too much, and it is best to wait for the screen to clear and not assume the delete didn't work.

I would like some clarification on how to actually set a master category if none is set, aside from the above-mentioned process.

I hope these comments are helpful.

Well I deleted it. So far no problems...