Testing for NULL in Numeric/Date Fields

[Goofus828]

Is there anyway to test for NULL in a date or numeric field with out getting the "Invalid function argument value, type, or count." error message in FoxPro for DOS?

I test for chr(0) in character fields with no problems and I know there is ISNULL() in VFP that works fine but I need this for DOS.

Thanks.

 

[TheRambler]

Try ISBLANK()

 

[Axworthy]

Try isempty()

 

[octavian2006]

In FoxPro for DOS don't exist NULL value.
But exist the EMPTY value.

 

[octavian2006]

And, of course, the function EMPTY().
Ex:
?EMPTY(date()) && .f.
?EMPTY({}) && .t.
?EMPTY(0) && .t.
?EMPTY(5) && .f.

 

[Goofus828]

I'm acutally working in Dos 2.5b. So Isblank() does not exist in that version.

 

[DSummZZZ]

I don't think there is a way to look for a null character in non-character field.
I think you would have to use low level I/O functions such as FOPEN(), FREAD() etc., to test for the existence of CHR(0). From there, you could calc the offset and see if it was in the position of a non-numeric field.


-Dave Summers-

Even more Fox stuff at:

http://www.davesummers.net/foxprolinks.htm

 

[Goofus828]

Thanks everyone. I did not think there was a way to find a null. I'll just keep pushing them to VFP!


Thanks again.