Difference between ISNOTNULL(string) and LEN(TRIM(string))&g

bireswar.goswami · Post by **bireswar.goswami** » Wed Jun 03, 2009 4:04 am

Hello All,

I am facing problem while using ISNOTNULL(string) and LEN(TRIM(string))>0.

It would be great if someone can please let me know what is the exact difference between them and when should I use what?

Thanks,
Bireswar

ArndW · Post by **ArndW** » Wed Jun 03, 2009 4:29 am

Bireswar,

there are a lot of DSXChangers who would help you, but only if you define "facing a problem". There is a very big and very fundamental difference between a NULL string and an empty string; once you get a grasp of that the question will most likely answer itself.

A NULL string is a string which contains an undefined value. An empty string is just a string which has a length of 0 and contains nothing. "Nothing" and "Undefined" are different. Also, a NULL string is undefined and therefore has no length (which is also different from 0 length)

dspxlearn · Post by **dspxlearn** » Wed Jun 03, 2009 8:29 am

I suggest this code:

Code: Select all

If IsNotNull(string)
Then if Len(Trim(string)) > 0
        Then <do something>
Else <do something>

ray.wurlod · Post by **ray.wurlod** » Wed Jun 03, 2009 4:03 pm

Consider the string "". This is not null, and has a length of zero.