Graded Homework

Create an ERD in Crow’s Foot notion that can be implemented in the relational model to represent and manage cities, counties and states in the US using the following description of attributes and assumptions:

The minimum attributes to be recorded for cities, counties and states are:

• For states: name, population and state capital (a city)
• For counties: name, population and the located state.
• For cities: name, population, the located state and the located county

There are some uniqueness assumptions:

• Names of states are unique
• Name of counties are unique within a state
• Cities are unique only within a state
• Some counties and cities have the same name, even within a state
• All cities are located within a single county