Conditional Custom Object, Lookup a Row or Create new Row
I'm looking to find out how to do my conditions(i think) I have two models 1 is standard Opportunities and other is a custom object, i'm am displaying data from the Opportunities and by default I am creating a new record for my custom object when saving data. What I am looking/wanting to do is by default with my custom object created a new record BUT if there is a related record that matches the Opportunity then display that row from the custom object with the data contained. Does this make since? FYI is the public force.com page.