How to build a query string for API_DoQuery when the matching value is a variable

Hi Guys,

I am currently working on a project to integrate ServiceNow with Quickbase. I have a question with regards to building a query when the value to be compared against cannot be hardcoded in quotes but it?s a variable instead. For instance based on the documentation for Quickbase APIs you build a query parameter this way:

{'fid'.operator.'matching_value'}

Now let?s say you don?t know what the ?matching_value? above is which means you cannot hard code the actual value but you want to use a value in some variable and that variable can be whatever your logic put in there, the question I then have is how would you build the query string in a use case like that?

For instance if I build my query string this way:

r.setQueryParameter('query', "{3.EX.'7635'}");

I get the desired results because I hard coded the matching value.

However in my use case for the type of the integration that I am building the user will populate the form with this value and when the record is created in ServiceNow I want to take this value and use it as a matching value when building the query in my integration script. Basically something like this  

r.setQueryParameter('query', '{3.EX.quickBaseId}');  

where quickBaseId is the value the user entered when creating the record that I want to integrate with Quickbase. This however does not work.

Would you guys please advise as to how can I build a query when the matching value is a variable.

Thanks,