EXERCISE
1.a) What is the definition of relational key and why it is needed?
A key consists of one or more attributes that can be identified in a row and relational key is an attributes that relates one entity with another entity in a relationship
Why is needed?
Relational key enables us to link the tables together in a database for easier data access storage
b) List and explain 4 types of relational keys
Candidate key: an attributes or group of attributes that identity a unique rows in a relation. One of the candidate key in chosen to be the primary key.
Primary key:any of the candidates that are selected to the key or an attributes that uniquesly identites each row in a relational table.
Foreign key: an attributes in one table where values must match the primary key in another table or whose value must not be full
Composite key: a primary key that consists of more than one attributes especially in (M.N) relationship
c) Based on the table given below, answer all the following questions
Borrower : Table
Borrower ID BorrowerName ContactNo Address category age datebirth
01-200506-002 Ali Ahmed 03-12345678 sental student 18 02 feb
01-200506-012 Aminah hasan 03-12345678 bandar baru student 20 15 feb
What is the name for the above table?
Borrower
What is the primary key for the above table?
BorrowerID
What is the data type for borrower’s name category age and date of birth columns?
Text
2.Based on the diagram know’s draw a complete entity relationship diagram (ERD) which includes entity attributes relationship,candinality constraints and by attributes.
| Housecode | Address | Rentalrate | Tenantcode | Tenantname | Startdate | Griddate |
| H0021 | SENTUL | RM560 | T0021 | Ali | 01/10/04 | 30/09/05 |
| H0022 | KAJANG | RM600 | T0022 | Aminah | 01/12/04 | 30/11/05 |
| H0023 | BANGI | RM850 | T0023 | Stephen | 01/01/04 | 31/12/04 |
| | | | | | | |
OwnerNo Housecode Tenantcode
OwnerName Address Tenant name
Rentaldate Startdate
| address |
| ownerhouse househouse |
Enddate
Based on the diagram above create a complete ERD which includes entity attributes,relational key and cardinality.
QUESTION 2
DR IDZHAM DENTAL CLINIC
Taman ulu kluang
Selangor
PatientID: KK 00120 Address: Bukit Antarabangsa
Patientname: Mr Richard Gene ICNO:450101-01-0121
RegistrationID: PP15412 Registration date:01/12/05
APPOINTMENT DATE/TIME
AppointmentID date time DoctorID DoctorName
B0001 05/12/05 2.00AM DD005 DR.Ali
B0002 15/01/06 3.00PM DD002 DR.Aminah
QUESTION 3
a)what is the meaning of database and database management system (DBMS)?
Database is collection is related data,designed to meet the information needed in an organisation and stores it in one specific location.
Database management system (DBMS) Is a collection of progress that enable user to create and maintain a database and provide control access to the database
QUESTION 4
Everyday,there are five doctors is on duty in orthopedic words .they are working on shif. A doctor can give a treatment to their patients and each patients can received a treatment from many doctor based on type of diseases. A patient can take a medicane could be town by many patients.
i. Doctor information is Doctor ID and Doctor Name
ii. Patient information is Patient ID ,Patient Name and address
iii. Medicine information is medicinecode and medicinename
iv. For each treatment it had type of treatment, it had type of treatment and cast of treatment
v. For each accepted medicine, it has a quantity and date
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