Reference no: EM1326108

1. Which of the following is not a step in the database design process?

Creating tables and columns from entities and attributes
Selecting primary keys
creating constraints and triggers

2. When an entity has a relationship to itself, we have a

archetype/instance relationship
recursive relationship
all the above

3. Given a table with the structure: EMPLOYEE (Empno, Name, Salary, HireDate), which of the following is not a valid ANSI SQL command?

SELECT COUNT(*) FROM EMPLOYEE WHERE Salary<30000;
SELECT COUNT(EmpNO) FROM EMPLOYEE;
SELECT HireDate, COUNT(*) FROM EMPLOYEE WHERE SALARY<30000;

4. To represent an association pattern in an ER model, _____

create a new ID-dependent entitiy with a 1:1 relationship to one other entity

create a new weak, but not ID-dependent entity with a 1:1 relationship to one other entity

create a new ID-dependent entity with a 1:N relationship to one of two parent entities.

5. The presence of one or more foreign keys in a relation prevents

the elimination of duplicated data
more complex SQL for mulitable subqueries and joins
all the above

6. Many-to-Many relationships are represented by

two tables with an M:N relationship
two tables with a 1:N relationship
by an intersection table which has M:N relationships with the two tables