Adding relation to repeat region table

Hi,

I want to create repeat region table in below format,

1. part number : if having reference_drg parameter with value (part number and reference_drg value should not same) then part_number = part_number + "N" other wise part_number = part_number

I have done above things and working fine. But getting issue that if model (part/asm) dont have reference_drg parameter then it is not showing part_number.

So please can someone guide me how to handle this case.

e.g. in below snap, sr.no. 4 & 5 don't have reference_drg parameter so it shows blank and that case i need to handle if it don't have this parameter then also show part_number

Thanks,

Prashant Pandarkar