Question

This question is from the test book Fundamentals of Database Systems, by Ramez Elmasri and Shamkant B. Navathe, (7th Edition), Addison-Wesley. which is from Chapter 4, Problem 30LE. I want a neat ER diagram and if possible explanation for this. I have an assignment submission in 8 hours please help me.

Consider a database system for a baseball organization such as the major
leagues. The data requirements are summarized as follows:
■ The personnel involved in the league include players, coaches, managers,
and umpires. Each is identified by a unique personnel id. They are also
described by their first and last names along with the date and place of
birth.
■ Players are further described by other attributes such as their batting orientation
(left, right, or switch) and have a lifetime batting average (BA).
■ Within the players group is a subset of players called pitchers. Pitchers
have a lifetime ERA (earned run average) associated with them.
■ Teams are uniquely identified by their names. Teams are also described by
the city in which they are located and the division and league in which
they play (such as Central division of the American League).
■ Teams have one manager, a number of coaches, and a number of players.
■ Games are played between two teams, with one designated as the home
team and the other the visiting team on a particular date. The score (runs,
hits, and errors) is recorded for each team. The team with the most runs is
declared the winner of the game.
■ With each finished game, a winning pitcher and a losing pitcher are
recorded. In case there is a save awarded, the save pitcher is also recorded.
■ With each finished game, the number of hits (singles, doubles, triples, and
home runs) obtained by each player is also recorded.
Design an enhanced entity–relationship diagram for the BASEBALL database
and enter the design using a data modeling tool such as ERwin or
Rational Rose.

Answer 1

Consider the following image-

Symbols used- U - it is for union. - Team is formed by the union of players , coaches and manager.

d - derived subsets - players , coaches,umpires and manager are derived subsets of personnel.