Am not getting the requirement exactly, but if you want to report on the data associated with a class, you need to create an RD rule on the class and have the properties of the class as the columns in the RD rule.
Since you mentioned Database, i am guessing that the DB might be associated with a class. So make sure the columns of the DB are mapped to corresponing properties in the external mapping tab of the class rule and also check for the Database Table rule that maps the class with the external table.
Once the above check is done, you can proceed to create a Report definition rule to report on the records of the Database table.
As per your attachment it looks like you are fetching the data from the database into the report definition. Now you created the PageList which contains same property names in the another class and you want to initialise the data available in the report definition into the Page List which is available in different class. Kindly let us know the version of pega, so that we can try an use case if this is your exact requirement.