Is it possible to query the database table with the rule inputs that are coming from nowhere?

Question

Hello, 
 I'm exploring the code of already built application and came to know that there is a query rule which is getting called by Parent Interface with no parameters being passed but inside the query rule there are several rule inputs on the basis of which the values are getting fetched from database table. Also I checked the application and its working fine, I'm just curious to know how can this be possible?

bryant.st39 · Accepted Answer

If the parent interface is not passing any parameters, then the query will execute without any queryFilters being applied. Based on how the query expression is built, the parameters are optional. If the query expression didn't handle null inputs, the query expression would likely return an error.