The image above has following textboxes. The textboxes in circled area are client data. The unique value in this textbox is GSTIN number, which is also a searchbox.
Now what I want is, if client is new, admin has to manually type the data. This data has to be stored in two tables i.e., Order Report and Client Report.
Now client report table should only add record if gstin number is unique i.e., there has to be no other records with same gstin number.
When you say unique, do you mean to check for no duplicates?
The code that you are showing makes a list of GSTIN in Client_Report table but remember that this is done when you start the app so it will be correct for the first entry. If you try to check for the same client again then you will still find it as new.