CSIS 325 – Lab 2 (ER Diagrams)

CSIS 325 – Lab 2 (ER Diagrams)

1. Using this completed instance diagram fill in the cardinality symbols for the ERD below. You will probably need to use a basic drawing tool within Word to draw the cardinalities.

Don't use plagiarized sources. Get Your Custom Essay on
CSIS 325 – Lab 2 (ER Diagrams)
From $8/Page
Order Essay

?
2. In the space provided below, draw an ER diagram containing Order and Customer entities connected by a 1-M relationship from Customer to Order. The relationship should be called “Places”. Define minimum cardinalities so that an order is optional for a customer and a customer is mandatory for an Order. For the Customer entity type, define attributes as follows: CustNo (primary key), CustName, CustBalance. For the Order entity type, define attributes as follows: OrdNo (primary key), OrderDate, OrdAddress.

Use ER Assistant to draw your diagram. Copy and paste the ERD from ER Assistant into the space provided below. [Note: To receive credit for this problem, you must use ER Assistant as your drawing tool.]

?
3. In the space provided below the following ERD, transform the following M-N relationship into an associative entity type and two identifying 1-M relationships.

Use ER Assistant to draw your diagram. Copy and paste the ERD from ER Assistant into the space provided below. [Note: To receive credit for this problem, you must use ER Assistant as your drawing tool.]

?
4. In the space provided below, draw a self-referencing entity type for the Employee entity type for which an employee is supervised by a maximum of one other employee and doesn’t have to be supervised by any employee at all. Conversely, an employee can supervise zero or many other employees. The attributes of the Employee entity are as follows: EmpNo (primary key), EmpName, EmpAddress.

Use ER Assistant to draw your diagram. Copy and paste the ERD from ER Assistant into the space provided below. [Note: To receive credit for this problem, you must use ER Assistant as your drawing tool.]

?
5. In the space provided below, draw a generalization hierarchy containing Employee, Administrator, and Faculty entities. The Employee entity is the supertype, and the Administrator and Faculty entities are the subtypes.

The Employee entity has attributes as follows: EmpNo (primary key), EmpName, and EmpAddress.
The Administrator entity has attributes as follows: AdmTitle, AdmContractLength
The Faculty entity has attributes as follows: FacTenure, FacRank

The generalization hierarchy should be disjoint but not complete.

Use ER Assistant to draw your diagram. Copy and paste the ERD from ER Assistant into the space provided below. [Note: To receive credit for this problem, you must use ER Assistant as your drawing tool.]

?
6. In the space provided below, draw an ER diagram that includes entities for Clients, Contracts, and Contacts.

Clients have the following attributes: ClientID (primary key), ClientName, ClientAddress.
Contracts have the following attributes: ContractID (primary key), ContractType, LicenseFee.
Contacts have the following attributes: ContactID (primary key), ContactName, ContactAddress.

Draw a relationship between Clients and Contracts such that a Client can be assigned to many contracts, but it can also exist without having any contracts at all in the database. Conversely, a contract can be assigned to only one client but must be assigned to a client in order to exist. Name your relationship “Signs”.

Draw a relationship between Clients and Contacts such that a client must be assigned to one and only one contact. A contact can exist in the database without being assigned to a client, but a contact can be assigned to more than one client. Name your relationship “Has”.

Use ER Assistant to draw your diagram. Copy and paste the ERD from ER Assistant into the space provided below. [Note: To receive credit for this problem, you must use ER Assistant as your drawing tool.]
?
7. Identify two problems with the ER diagram below:

_________________________________________________________________________

_________________________________________________________________________

?
Use the following ERD to answer the next 2 questions:

8. What is the primary key of the WorkHours table?

Answer: _______________________________________________________________

9. Indicate the redundant field in the Employees table.

Answer: _______________________________________________________________
?
10. Short Answer:
When converting the ERD to a table design, how should you handle the AssignedTo relationship? (Be sure to include a discussion of primary keys, foreign keys, and tables in your answer.)

Answer: _______________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________

11. True/False
ProjectID will be a foreign key in the Employees table to reflect the “Manages” relationship.
Answer: _______________________________________________________________

12. After converting the ERD to a table design, what fields will be present in the Contracts table? Indicate the primary key of the table by underlining the appropriate field(s).

Answer: _______________________________________________________________

13. Short Answer:
WorkHours is a weak entity.
What would you do to transform it into a strong entity?
Answer: _______________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________

14. Short Answer:
Would it be desirable to change WorkHours into a strong entity? Why or why not?

Answer: _______________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________

Calculator

Calculate the price of your paper

Total price:$26
Our features

Top Homework Writers is here for any paper writing help you need!

Need a better grade?
Custom Paper Writers got you covered.

Order your paper

Save More. Score Better. Use coupon code SPECIAL20 for a 20% Discount