How to use SQL functions inside Innovator for large and complex queries?

Hi community,

inside Innovator the "SQL" ItemTypes contains some Procedures, Functions and other things used for internal purposes:

It´s also possible to add own custom items. Common for example is the use of procedures that can be called e.g. this way:

Item callframe = this.newItem("SQL","SQL PROCESS");
callframe.setProperty("ARG1", source_it.getProperty("name"));
callframe.setProperty("ARG2", source_id);
callframe = callframe.apply();

In  my case I want to store a pretty huge SQL query as function within the SQL ItemType. Unfortunately I don´t know how to call these kind of functions from my Method. Does any one has an idea how we can use Functions?

Many thanks for your help!