Group and filter null field in cross tab row group

[Kelum]

I just creating a report that can count number of student for a specific age group .using database record i'm generating those reports

Here it looks like

Age                |  Count

18                   |   344

20                   |   356

30                   |   567

Age Unknown |   323

Age 18, 20 , 30 , I able to count using following Edit Grouping and Edit Filtering options

for example , to count age 18 

in Edit Grouping : = Fields.Age = 18
in Edit Filtering   :  

Expression       | Operator | Value
= Fields.Age     |       =       |    18

I want to get count for "Age Unknown" group if age column null in database , what is the grouping and Filtering syntax for that in telerik 

[Nasko]

Hello Kelum,

You can use the IsNull() function to check the Age column in the database e.g.:

= IsNull(Fields.Age, True) = True

In this example if the Age field is Null the function will return True, otherwise it will return the Age data field value.

Regards,
Nasko
Telerik

[Kelum]

How can I put that in Edit Grouping and Edit Filtering  ?

[Nasko]

Hello Kelum,

You can use the same template provided in your first post:

= IsNull(Fields.Age, True) = True

or

Expression | Operator | Value
= IsNull(Fields.Age, True) | = | = True

Regards,
Nasko
Telerik

[Kelum]

your previous solutions working for integer when I try to use string it give this error message

"Cannot perform '=' operation on system.string and system.Boolean

How can I check string values ?

[Nasko]

Hello Kelum,

When the data field is of type string you should also pass a string value to the IsNull function's second argument:

= IsNull(Fields.SomeStringField, "NullReplacementString") = "NullReplacementString"

Regards,
Nasko
Telerik

[Kelum]

Thank you very much for your assistance, because of your correct guidance I able to complete my telerik report,

Thanks Lot 
 K