A function_call can consist of a call to either SQL Functions or a 4D function (4d_function_call). Both types of functions manipulate data and return results and can operate on one or more arguments.
 
    This example uses the SQL COUNT function:
  C_LONGINT(vPersonNumber)
 Begin SQL
    SELECT COUNT (*)
    FROM SALES_PERSONS
    INTO :vPersonNumber;
 End SQL