Database Reference
In-Depth Information
Figure 5-7. In this picture, the solid lines represent relationships you've identified among the entit-
ies. The dotted lines show relationships you don't have to explicitly create—they're implied. As
long as there's a path—any path—from one entity to another, they're related. You don't need a dir-
ect path.
When you make your ER diagram, you should get rid of redundancy in your relationships. In
other words, remove lines that show direct relationships when the relationship is already im-
plied by other entities and relationships. If you don't do this now, you'll have trouble creat-
