How to check null value?

[harleen_singh]

hello,

I am checking the null value in variable Filter like this.

               Let Filter=trim(peek('Filter',$(i),'TableNames'));

IF not IsNull($(Filter)) THEN

//code

ELSE

//code

ENDIF

I want to check if Filter gets null then code after ELSE should go

and if Filter gets some string the code after IF should go??

is it correct??

when i get string value in filter varialbe it shows errror

thanks

Lavi

[#2]

The code seems to be correct.

Which error do you get ?

[SunilChauhan]

may be in place of let you need to write set

because if you create varible using set then it is calculated uing $ sign expression

and let will calculate directly

other wise code looks good

hope this helps

[harleen_singh]

@sunil,

            Can u see i have used Peek function which doesn't work when i use set

thanks

[harleen_singh]

Philippe Motillon

This is the error i am getting

Script line error:

IF not IsNull(De Kil Kraanbedrijf) THEN

see when the string value comes in the Filter variable it gives error. But when null comes in it is okay.

thanks

[SunilChauhan]

but it iwll get calculated when you use

$(Filter)

please try once and then let me know

[SunilChauhan]

            Let Filter=trim(peek('Filter',$(i),'TableNames'));

IF not IsNull($(Filter)) THEN

//code

ELSE

//code

ENDIF

you need to define $(i) also

[jonathandienst]

Lavi

I think the problem is the $ expansion of Filter inside the IsNull() function. This cause the 'evaluated' value of Filter to be passed to IsNull, which is probably invalid and therefore causing your error.

Instead of IsNull($(Filter)), use

Let Filter = ....

If Not(IsNull(Filter)) Then

Else

End If

Regards

Jonathan

[sridhar240784]

Hi,

You may need to add single qoute around the '$(Filter)' variable when you check not isnull since you are using LET variable.

When you use the LET varibale, your expression is already calculated and your variable will have the resultant value. If you again equate the 'Filter' variable with variable expansion $(Filter) when your variable is holding null value then you`ll get script line error.

Have a look at the attached application.

Let Filter=trim(peek('Filter',$(i),'TableNames'));

IF not IsNull($(Filter)) THEN

//code

ELSE

//code

ENDIF

Hope this helps you.

-Sridhar