You might restructure your specifications into a group of records for each item instead of one record with many unused fields.
Each record might have three fields: Sku, Label Field, Data. You might add a fourth field for units.
Then your portal can list this group of records to show the specifications for a given SKU.
Thank you for your reply.
I dont get your response. Sorry if I wasnt clear about the structure of the database.
What I have now is one record per item, each record have all the fields I need for each item, in this main table all fields are common for all items, (Sku, name, purchase model, manufacturer, etc). Specifications are on a related table, again, one record for each Sku. In this table I have all specifications that apply for all items, one field for each specification. records on this table are filled only with the fields that apply for each Sku, the rest are kept empty.
Portal is on the items layout using data from the main table and showing related fields on the portal from the specification table.
Solution need to show me a portal with only related fields that have a value for the Sku.
What I am suggesting is that you change that very structure that you have so that you have something that handles the variable specification values more flexibly by using a set of records with just a few fields instead of one record with many fields.
This also seems a better use of your portal since a portal is usually used to display multiple records yet in your current design you appear to have one record with one SKU matching to one Specification record.