A couple of things I have come across while working on a side project:
1) The table relationships seem to ignore multi-column relations
currently. The data is set up to accept it, but looking through the code
itself it appears that each column of a FK results in its own Relationship
object. I am working around it currently based on the code in MetaModel, but
I wanted to see if I was missing something in the existing code. Currently if
I have a three-column FK constraint I end up with three objects when I list out
the results of table.getRelationships(), such as:
Relationship Object 1
Primary Table: P
Primary Column: [a]
Foreign Table: F
Foreign Column: [a]
Relationship Object 2
Primary Table: P
Primary Column: [b]
Foreign Table: F
Foreign Column: [b]
Relationship Object 3
Primary Table: P
Primary Column: [c]
Foreign Table: F
Foreign Column: [c]
There is currently no way that I see to denote that these three Relationships
actually comprise one complete FK. What I would have expected would have been:
Relationship Object 1
Primary Table: P
Primary Column: [a, b, c]
Foreign Table: F
Foreign Column: [a, b, c]
I can get to this level if I look at the values returned by getImportedKeys and
use the FK_NAME/PK_NAME properties. The documentation says that these values
could be null, so is there a time where you could have a multi-column FK with
no name? It looks like ORA and MSS (what I am concerned with) would auto-fill
the name if one is not provided.
2) Having to load the entire schema's relationships to get to one table's
relationships is REALLY expensive in my case. Does it not make sense to have
table.getRelationships() only worry about its own and then store the
information as it is loaded at that level?
Looking at the code the pieces are there to essentially do both of these, so I
am wondering if I am just missing something or if these are features planned
for further down the road?
Thanks...
Mike
