You have now seen how to link data together based on a common key field using a join or relate, as well as based on a spatial relationship using a spatial join. These methods are extremely useful. However, they do have limitations. Joins and relates only exist in a single map and do not transfer easily to other maps or projects. Spatial joins create new feature classes or tables while still leaving the original data unaltered. So, is there a way to permanently link two tables or two feature classes together?

Yes, if the data is all in the same geodatabase. Geodatabses allow you to create a relationship class that permanently links data together. That link carries over into any map, scene, or project that uses that data. You can create a relationship class between two feature classes, two standalone tables, or a feature class and a standalone table.

Relationships not only link data together but also impact the behavior or contents of the linked...