Describe and provide an example of an entity-relationship (E-R) diagram.
E-R diagrams are used to show relationships between the data in two different tables. The relationship is established with the help of foreign-key. The foreign key is the name of a certain table column that is used to relate its table to another table. Following is an E-R for two tables in a non-profit organization that collects donations from different people. These tables are from my Access database for another assignment.
In the Figure 2, we can see the relationship diagram between the two tables. The DonorID is acting as a foreign key.