I'm looking in to extending the Calendar module with some custom functionality. Among other things I need to extend the database with some custom tables of my own and therefore it would be very helpful with some sort of ER diagram over the existing tables, to understand how things are connected.
Thank you very much for your reply. I'll look in to the custom fields module as well, we are actually paying customers, but I'm currently developing against the open source version, since I'm not familiar with how access to sources work for the paid version.
ER diagram is a graphical representation of database which includes entities,attitudes and relationship.It stores the data. And it is data modeling technique that graphically illustrates an information system’s entities and the relationships between those entities.
The main elements of an ERD are: