I think it is just my thinking that is off here. Suppose I have two entities: question and choice. A question can be a parent or child, or both (in relation to other questions). It seems that this ...
Does this situation call for well specified associations, single table inheritance, or polymorphic association?
I'm building a web-app where users can keep track of who owes whom money. I have users and debts. Given a user I want to be able to find out all the debts to other users, and all the loans to other ...
I have three entities : Technician Vehicle Repair The question is how to model this in ERD? Knowing that a technician can repair multiple cars, and the same car can be repaired by one and only one ...
I work in healthcare IT, reviewing data management processes of various observational studies. One problem I have repeatedly faced is the poorly encoded data, especially when some values are missing. ...
I'm looking for an application to create simple diagrams for database design. I'm not looking for anything that will help create the databases, just a simple tool for a design report. I have tried ...