Retrieving the "many" side of a link in a table which was deleted

[Karl_at_Easy_La]

Take the example below, imagine you have:

• Category.Products
• Product.Category

A product is linked to multiple categories. When you first create the 'Category' field on Product, this creates the other side on Category, lets call it "Products".  If you delete the column "Products" from the Category, is it possible to re-link them later on?

Also, if you do not think one will ever need the "many" side of the relationship - does it slow AirTable down if you keep that many-side Field as well? Or it does not make a difference?

[Alexey_Gusev · Accepted solution]

Hi,
Yes, it's quite easy, especially if your Category table has unique primary field. When you delete the column "Products" from the Category, other side column ('Categories' in Product) became single text. Just create new linked field in Product and copy-paste whole column there. The shorter way is to edit this single-text field and turn it back to linked.
But if your primary field (in Category Table) is not unique, it's harder. When you copy-paste column of values into linked field, for each pasted value it searches for record to link with the same value in primary field. If it can't find such value, it creates new record with such name in primary field.

One to many is a usual way to link, established in most cases, because when you have strong one-to-one relation, you might want to put all data in the same table to avoid unnecessary complexity.