While doing this, I am getting the below error randomly.
While doing what? You didn't show us any code. And how often is "randomly"? Every time, every other time, once a week?
Error Invalid value for field 'Sales Area'
Is all your data valid? Check the row of data where the failure occurred and make sure "Sales Area" has a good value. Try a simple query that would give you this row and display "Sales Area" and see if that fails.
I am trying to print the value returned from function which reads DB value and even though it is printed properly in function, it is not returning anything here. I am checking the same.
Show us the code please.
