Dick, you say that there is no such thing as "NULLS" or "BLANKS".
You just made a very wrong
quantum leap. . . There probably should never be a thought that has "null" and "blank" together - they have nothing to do with each other. . . Simply said (again) - there is no such thing as a null in a pic x field.
If someone in your organization wants to call a space a null, that is just ignorant. They need to learn that a space (x'40') is not a null (which by definition has no value).
I remember using the check such as variable = spaces or not !!
Sure you do - we all do that. When we do that, we are not checking for null we are checking for some number of x'40's.
If so, why do we use NOT NULL while creating DB2 fields for tables
Some database management systems support the null concept - some do no. When you check for "null" or "not null" the comparison has nothing to do with spaces/blanks.