You can use
[$id] instead of
[QueryString:id], for example in a grid’s data source you can set as statement:
select * from Users where UserID=[$ID=1]
If I access a page with no id in query string, then the -1 id will be taken as default and no value will be returned because there is no user with -1 id.
* I have seen it written that MyTokens was necessary in order to use this notation, however it worked for me without MyTokens.
The following might work only when MyTokens is installed
Default values are supplied when the token is invoked, this method works for any token and it will override the default value that is specified for custom tokens when they are defined.
The syntax is: [MyNamespace:MyToken = My text value that is displayed if there is data returned by the token]
For example, [GET:SomeParam=21] will return 21 if a parameter with name SomeParam doesn’t exist in Query String.
If you want to hide something if the querystring parameter does not exist, then it looks like this: [QueryString:WEID=0]!="0"