Dennis,
What's the settings for EQNULL ?
Correct evaluation of expressions when EQNULL is SET to ON.
R:BASE 6.5++ (Build:1.866xRT03 and higher)
R:BASE uses special processing on simple IF commands for maximum speed. However, the way these were processed was not consistent with the way complex IF commands or WHILE commands were processed with regard to comparisons using NULL values. The EQNULL setting at TRUE means that a comparison between two NULL values is a match and that a comparison between a NULL value and a non-NULL value is not. When EQNULL is set to FALSE then a comparison between two NULL values is not a match nor is a comparison between a NULL value and a non-NULL value a mismatch. The NULL value essentially make the whole thing "unknown'. This behavior was followed in WHILE and complex IF commands but was not followed in simple IF commands. A simple IF command has only one comparison and the left side is a simple variable and the right side is either a variable or a constant. A simple IF does not have any expressions.
Compare these code samples:
SET VAR v1 TEXT = NULL SET VAR v2 TEXT = NULL
SET EQNULL OFF IF v1 = .v2 THEN -- will not be a hit ENDIF IF v1 <> .v2 THEN -- will not be a hit ENDIF IF v1 <> 'This' THEN -- will not be a hit (it used to be before this fix) ENDIF
SET EQNULL ON IF v1 = .v2 THEN -- will be a hit ENDIF IF v1 <> .v2 THEN -- will not be a hit ENDIF IF v1 <> 'This' THEN -- will be a hit ENDIF
Before this fix, the comparison "IF v1 <> 'This' THEN" would be a hit with EQNULL set ON or FALSE when it should only be a hit when EQNULL is ON. This means that now:
"IF (.v1) <> 'This' THEN" and "IF v1 <> 'This' THEN"
will both process the same way. In the past they would be different because of this problem.
In your code if you want the comparison of a NULL variable and a non-NULL constant to be a hit then you should run with EQNULL set ON.
In your code if you want the comparison of a NULL variable and a non-NULL constant to be a hit then you should run with EQNULL set ON.
Let me know how that goes ...
Hope that helps!
Very Best R:egards,
Razzak.
At 12:42 PM 10/7/2003 -0700, Dennis McGrath wrote:
I've got a problem has me stumped. I have a client where SET ZERO is always ON. I won't go into the details, but this is a must.
Running the latest patch of 6.5++ both DOS and Win.
I need to test a column (REAL) on several entry forms to see if it is NULL or zero. Seems the ISNULL function is not up to the task. Here is some demo code:
set null -0- set zero on -- required set var vreal real = null set var vtest = (ifnull(.vreal,'is null','is not null')) wri .vreal, .vtest wri ' ' set var vreal real = 0 set var vtest = (ifnull(.vreal,'is null','is not null')) wri .vreal, .vtest
vTest always = 'is null'
Anyone have a magic bullet that will solve my problem?
