What happens in the database when you link variations in woocommerce? [closed]

Well I have found the issue. I thought that I had it sussed when I was adding in the _attribute_size to my postmeta for the variations. However, i had miss read it for close to 5 hours as it should have been attribute_size (size being the name of the attribute that I was adding).

Feel stupid however, this answer may be useful to others who are trying to do the same sort of thing.