IsNull and shared variables

[dean12]

Doesn't appear to me that I can do this:

shared StringVar abc;

if IsNull(abc) then abc = "xxx"


Seems CR8.5 says "A field is required here" and points to the argument for the IsNull function.

Guess it is not possible to test for nulls on declared variables?

 

[Ngolem]

so you are passing a variable from Subreport to main and want to know it is null??

rather than use ISNull make the variable = "" when whatever condition exists to cause it then test it like this

shared StringVar abc;

if abc = "" then abc = "xxx"

that should work....also consider adding "WhilePrintingRecords" to the formula...unless the formula is used for grouping or summary purposes I always do this.


Jim Broadbent

 

[MrBillSC]

dean,
I think your field needs to be in brackets
If isnull({abc}) then {abc} = "xyz"

Hope this helps.

 

[JoeCrystal]

The definition of IsNull(fld) states that fld must be a valid database, memo, or BLOB field. Using a shared variable is not valid. By the way a shared string variable is equal to "" if not initialized.

 

[Guest_imported]

This will probably throw and error because IsNull requires a TRUE\FALSE answer


Your most likely to have success with

if IsNull({abc})=True then
{abc} = "xxx"


hth...Brad

 

[Guest_imported]

This will probably throw and error because IsNull requires a TRUE\FALSE answer


Your most likely to have success with

if IsNull({abc})=True then
{abc} = "xxx"


hth...Brad

 

[synapsevampire]

shared StringVar abc;
if IsNull(abc) then
abc =: "xxx"

Don't use just an equals sign.

-k

http://www.informeddatadecisions.com

kai@informeddatadecisions.com

 

[synapsevampire]

Sorry, typo:

shared StringVar abc;
if IsNull(abc) then
abc := "xxx"

-k

http://www.informeddatadecisions.com

kai@informeddatadecisions.com

 

[JoeCrystal]

You can NOT use a Shared Variable in IsNull().

 

[synapsevampire]

Ahhhh, interesting, thanks JoeCrystal, I should have paid better attention to Ngolems post. Apparently you can't use isnull against any variable.

I guess they need to use:

shared StringVar abc;
if abc = "" then
abc := "xxx"

The problem of the = vs. := was the only error.

-k

http://www.informeddatadecisions.com

kai@informeddatadecisions.com

 

[Ngolem]

Well...thank you SV....I was wondering when/if people would get back to my approach Jim Broadbent

 

[aklein]

DBA_Frog said:

This will probably throw and error because IsNull requires a TRUE\FALSE answer


Your most likely to have success with

if IsNull({abc})=True then

IsNull requires the name of a field to test for null.
IF requires a true/false argument, but IsNull returns one.

Testing a function like IsNull for True is a waste of execution time - If IsNull() means "if it's true".