Questions & Solutions.
Object in the real word with an independent existence that can be Entity
differentiated from other objects, has a physical existence, and a
conceptual existence.
What are the characteristics of a relational database? -Values are atomic
-Column values are of the same kind
-Each row if unique
-the sequence of columns and rows are insignificant
-Each column has a unique name
Candidate Key The set of all keys that are eligible to become unique keys
Keys that are generated by the DBMS Surrogate keys
Given the relations: SID is the primary key
STUDENT (SID, StudentName, Major, AdvisorID)
Which of the following is true in reference to the STUDENT table
A primary key is All of the above
All of the above
used to identify unique rows
a candidate key
used to represent rows in relationships
Incorrect Response
required to be unique
When the primary key of one relation is placed into a Foreign Key
second relation, it is called a
Feild Key
Foreign Key
Primary Key
Candidate Key
Compisite Key
1/9
, Identify the themes in the relation below DOCTOR, PATIENT, INSURANCE
TREATMENT(DoctorID, DoctorName, DoctorPhone, PatientID,
PatientName, PatientPhone, InsuranceName, InsuranceType,
InsuranceContactNumber)
DOCTOR, PATIENT
DOCTOR, HOSPITAL
DOCTOR, PATIENT, HOSPITAL
DOCTOR, PATIENT, INSURANCE
A candidate key is/can All of the above
used to represent rows in relationships
a candidate to be the primary key
All of the above
Can consist of composite keys
required to be unique
Which of the following is true about a relation? All entries in any column must be of the same kind
All entries in any column must be of the same kind
A relation may have duplicate rows
The order of the columns in a relation must go from largest to
smallest
A relation may have multiple names
A relation may have duplicate column names
In relational tables, the primary key should always be assigned not true
null values
True False
2/9