Required Values in field from SQL Data

Hello all, Happy New Year and all that!

I'm back at it already and have hit my first hurdle with using ESS (now the DSN is working that is!)

I have several SQL views on a read only DSN which I'm pulling through to FM.  The first view has data relating to our customers and this is pulled from our ERP, which is the system of record, hence the data is read only.

The problem I have is that there are four fields that are showing as "required values".  The first 3 are indeed required and will always be populated, the fourth (ID of parent account) however is only likely to be populated about 10% of the time in the ERP data.

Of course when I edit any local fields which I've added to a layout using a related FM table, the solution validates the data from SQL and complains that the parent account ID field is empty, but of course I can't fill this in as the data is read only and set to can't edit... vicious circle! -worryingly I originally typed viscous circle which is a completely different thing! 

Can anyone advise why this field is insisting on being populated - does it come from the SQL data, e.g. some kind of primary key? If I remove the "required value" bit from the field in manage database it just reappears.

Thanks for any help you can offer.

Regards,

Tim

Edited January 5, 201610 yr by Cerbera