Removing field entries based on a list, based on another field
So i have a database with a bunch of tables. One is a table called 'items' with properties such as price, amount, category, etc. Then another table for the categories, with fields like category name, description, etc.
The category field in 'items' uses a data entry from a list that is based on a the category name field in the other table.
If i delete the category, how can i clear the 'item' category name field for the records that have chosen the category that was just deleted? Or is there a better way to link a item record to a catagory record?