Chapter 3
How many optional columns will the relational schema mapped from the ABC Retailer ER diagram have? 0 1 2 3 4
0
How many tables in the relational schema mapped from the Eaglerun Trucking Dispatcher ER diagram will have composite primary keys? 0 1 2 3 4
1
If an entity has two unique attributes, how many primary keys will its mapped relation have? 0 1 2 3 4
1
Observe the ER diagram for the CENTRAL SCHOOL LIBRARY. How many columns will the relation LIBRARY BOOK have in the relational schema mapped from the Central School Library ER diagram? 4 6 3 5 2
2
How many columns will the PROMOTION table have in the database from the ABC Retailer ER diagram? 2 3 4 5 6
3
Observe the ER diagram for the ABC Retailer. How many entities are represented from the ABC Retailer ER diagram have? 3 1 5 4 2
3
Observe the ER diagram for the Eaglerun Trucking Dispatcher. How many columns will the relation DRIVER have in the relational schema mapped from the Eaglerun Trucking Dispatcher ER diagram? 1 3 0 4 2
3
How many columns will a relation resulting from mapping the entity Employee have? 3 6 5 2 8
6
Autonumber data type option: Automatically converts the existing data type into a number type Assigns a number to each of the used data types Enables automatic counting of columns in a table Enables automatic counting of tables in a database Enables automatic generation of consecutive numeric data values in a column
Enables automatic generation of consecutive numeric data values in a column
A foreign Key column must have the same name as the primary key column it refers to. (T/F)
False
Within one relation, two rows can be identical.(T/F)
False
Tuple is a synonym for: Relationship Column Field Row Table
Row
If a 1:M relationship is optional on both sides, which of the following is true? The resulting foreign key can have null (empty) values The resulting foreign key cannot have null (empty) values The resulting foreign key must have null (empty) values No foreign key is created as a result of mapping such a relationship Two foreign keys are created as a result of mapping such a relationship, one that can have null (empty values) and one that cannot have null (empty values)
The resulting foreign key can have null (empty) values
If a 1:M relationship is mandatory on both sides, which of the following is true? The resulting foreign key can have null (empty) values The resulting foreign key cannot have null (empty) values The resulting foreign key must have null (empty) values No foreign key is created as a result of mapping such a relationship Two foreign keys are created as a result of mapping such a relationship, one that can have null (empty values) and one that cannot have null (empty values)
The resulting foreign key cannot have null (empty) values
An entity relationship diagram is a visual depiction of the relational database model.(T/F)
True
Every attribute appears only once in an ER diagram. (T/F)
True
Two columns of a relational table can have the same values. (T/F)
True
Two columns of a relations table can have same names. (T/F)
True
Which of the following is NOT true? In a relational database: Two tables can be a part of the same database Two tables, in the same database, can have the same name Two tables, in the same database, can have the same number of columns Two tables, in the same database, can have the same number of rows A foreign key column of one table is related to a primary key column of another table
Two tables, in the same database, can have the same name
Relation is a synonym for the following construct in a relational database Relationship Column Field Row Table
table
