Define workbook export parameter default value

[Cameron_Stephens]

I have a number of Sentinel workbook queries where I click on a value in the 1st query which is then exported as a parameter to be used in a 2nd query. This is working great except when the workbook is first loaded, because I haven't clicked on anything in the 1st query, the 2nd query displays the following error. How can I specify a default value to satisfy the query until I click on a value?

Query could not be parsed at ')' on line [2,21] Token: ')' Line: 2 Position: 21

The first 2 lines of the 2nd query look like this:

let ActivityType = dynamic({AType});
CloudAppEvents
| where...

Any help to resolve this error is appreciated.

[#2 · Accepted solution]

@Cameron_Stephens 

The alternative method is to "hide" the other queries until the first has been selected - its also much neater on the screen

[#3]

Thanks @Clive_Watson, tested and working.

I had seen that, but wasnt able to make it work as I was trying to use null or empty as the parameter value, I didnt think to go with "not set"