How to read a data model
This modeling tidbit excerpted from Data Modeling Made Simple

You need to know only three symbols to read any relationship. The small vertical line means “one.” The circle means “zero.” The triangle with a line through the middle means “many.” Some people call the “many” symbol a crow’s foot. ..
Sharpen your skills!

Data Model Scorecard™
The standard for data model quality. 10 areas to validate your model.
Data modeling training starts early!
I usually recommend data modeling training shortly after potty training. In our first formal data modeling lesson, I was impressed how quickly Sadie and Jamie were able to pick up the basic modeling concepts. If you look closely at this picture, you will notice on the data modeling tool we are using, the Doodle Pro, the two entities CHILD and TOY have a many-to-many relationship. This was not only a lesson in data modeling but also a lesson in sharing. A CHILD can play with many TOYs, and more importantly, a TOY can be played with by many CHILDREN. Unfortunately, a toy being played with by more than one child is a rule which is still being debated within our household!

