Null Table Field Values

Description

Alpha Anywhere does not really have the concept of a NULL value for a table field value. If you want to test if the field is empty, then you use these expressions:

The following table details null values for various Xbasic data types.

Data Type	Code	Comment
Character	C	= ""
Date	D	= ctod("")
Numeric	N	You cannot distinguish between records that have no value, and those that have a 0 in them. The .DBF table format, which Alpha Anywhere uses, has no concept of a NULL numeric value. = 0
Logical	L	You cannot distinguish between records that have no value, and those that have a .f. value. = .f.
Time	T	= 00/00/0000 12:00:00 00 am
Short Time	Y	= 12:00:00 00 am