Thousands of Objects in a Graph

 

 

 

Looking at the names you use and the examples, I wonder if you might actually want something else. If Entity_With_Attributes only ever has one Entity, then make that a separate property, of Datatype Entity, and you can have the second property, a Collection of Attirbutes, without needing to allow contents of different types.

 

Alternatively, if what you really want is to draw the Entity_With_Attributes as a big box that contains attributes, you may want it not to have properties, but to simply visually contain the Entity and Attribute objects that you put in the graph. You can then use the MERL commands, contents and containers, to access this information both for rules (making the symbol show an error if the enclosure is wrong) and generation.

 

What is the semantics of ER diagram (type B)? And why do you want two different graphs showing the same thing (in this example at least)? Think about whether the objects in the lower graph are identical to those in the upper graph, or are themselves new objects that refer to the objects in the upper graph. Think about whether you can use 'convention over configuration', e.g. if the default situation is that a Type A graph has a roughly isomorphic Type B graph, then you don't need to draw the Type B graph, since it adds no information: you can already generate what you want directly from the Type A graph.