I have a 'material' table and a 'composition' table.
'composition' has 2 foreign keys: 'Input' and 'Product'.
'material' primary key is 'Id'.
I created two 1 to many relationships: Id --> Input and Id --> Product.
Although this works well in "real life" (in the database schema), I was not able to represent it in Visio 2003 using the ERD database modeling tool. If I try to associate Id to Product after having associated Id to Input, Visio simply changes the previous association to the new one. I can never have both at once. (I am not using reverse engineering at this point)
How can I document this ERD with Visio?