Deck 4: Constraints

Question 1

Any constraint can be created at the table or the column level.

Answer 1

False

Question 2

A primary key is usually given the abbreviation _pk in the constraint name if the name is assigned by the user.

Answer 2

True

Question 3

The table level approach can be used to create any constraint, except a CHECK constraint.

Answer 3

False

Question 4

Only one PRIMARY KEY constraint can exist for each table.

Question 5

A constraint name can consist of up to 10 characters.

Question 6

A FOREIGN KEY constraint will not allow a row containing a NULL value in the foreign key column to be added to the table.

Question 7

A foreign key constraint can only be created at the column level.

Question 8

A CHECK constraint requires that a data value meet a certain condition before the record is added to the database table.

Question 9

The CONSTRAINT keyword is required if the user is going to assign a name to a constraint.

Question 10

A FOREIGN KEY constraint can be added to the column of a table to ensure that the referenced data value actually exists in the other table.

Question 11

A constraint for a composite primary key must be created at the table level.

Question 12

Constraints are used to ensure the accuracy and integrity of the data contained in the database.

Question 13

Constraints are rules used to enforce business rules, practices, and policies.

Question 14

A constraint is always enforced at the table level.

Question 15

A NOT NULL constraint can only be created at the column level.

Question 16

A constraint can only be created as part of the CREATE TABLE command.

Question 17

The MODIFY clause is used with the ALTER TABLE command to add a PRIMARY KEY constraint to an existing table.

Question 18

A PRIMARY KEY constraint will make certain the column designated as the primary key does not contain a NULL value.

Question 19

A UNIQUE constraint is the same as a PRIMARY KEY constraint, except that it will accept NULL values.

Question 20

If a FOREIGN KEY constraint exists, then a record cannot be deleted from the parent table if that row is referenced by an entry in the child table.

Question 21

If a(n) $\underline {\text { FOREIGN KEY } }$ constraint has been created for a table, it means the data values in that column must be unique and cannot contain NULL values. _________________________

Question 22

If a data value violates a(n) $\underline { \text { constraint } }$ , the entire row is prevented from being added to the table. _________________________

Question 23

A(n) $\underline { \text { FOREIGN KEY } }$ constraint is used to ensure that referential integrity exists between tables. _________________________

Question 24

A constraint can be added to a table after the table has been populated with data even if the existing data violates the constraint.

Question 25

The ALTER TABLE command can be used to disable a constraint.

Question 26

A NOT NULL constraint can only be created at the $\underline {\text { table } }$ level. _________________________

Question 27

A constraint can be renamed using the ALTER TABLE command.

Question 28

The SYSDATE can be used as a condition in a CHECK constraint.

Question 29

The ALTER TABLE command with the ENABLE clause can be used to enable a constraint.

Question 30

The default name for a constraint is $\underline {\text { SYS Cn } }$ where n consists of a number that will make the name unique within the database. _________________________

Question 31

A constraint name can consist of up to $\underline { 25 }$ characters and numbers. _________________________

Question 32

In the USER_CONSTRAINTS view, the constraint type for a PRIMARY KEY constraint will be listed as PK.

Question 33

A(n) $\underline { \text { constraint } }$ can be created during the creation of a database table or added to a table afterwards. _________________________

Question 34

When dropping a constraint, the user is always required to specify the name of the constraint being dropped.

Question 35

The $\underline { ADD }$ clause of the ALTER TABLE command is used to add a PRIMARY KEY constraint to an existing table. _________________________

Question 36

A $\underline { \text { Datatype } }$ is a rule used to ensure the accuracy of data stored in a database. _________________________

Question 37

Any type of constraint for a single column can be created at the $\underline { \text { column } }$ level. _________________________

Question 38

With the exception of the NOT NULL constraint, constraints can be added to a table using the ADD clause of the ALTER TABLE command.

Question 39

A NOT NULL constraint is a special FOREIGN KEY constraint.

Question 40

Each column can only be included in one constraint.

Question 41

Which of the following statements about a PRIMARY KEY is incorrect?

A) It identifies which column(s) uniquely identify each record.
B) It can be NULL, as long as the FOREIGN KEY contains a value.
C) Each data value must be unique.
D) none of the above

Question 42

A(n) $\underline {\text { NOT NULL } }$ constraint is a special CHECK constraint with the condition of IS NOT NULL. _________________________

Question 43

The ALTER TABLE command with the $\underline { \text { MODIFY } }$ clause can be used to disable a constraint. _________________________

Question 44

When a FOREIGN KEY constraint is being created, the $\underline {\text { REFERENTIAI } }$ keyword is used to indicate the table being referenced. _________________________

Question 45

Which of the following is a valid statement?

A) Constraints are rules used to enforce business rules, practices, and policies.
B) Constraints prevent errors by not allowing data to be added to tables if the data violates specific rules.
C) Constraints ensure the accuracy and integrity of data.
D) all of the above

Question 46

The $\underline {\text { REFERENCE } }$ constraint is used to ensure that a data value meets a specified condition before a record is added to a table. _________________________

Question 47

If the ON DELETE CASCADE keywords are included when a(n) $\underline { \text { PRIMARY KEY } }$ constraint is created, then if a row is deleted from the parent table, any corresponding records in the child table are also deleted. _________________________

Question 48

Both the $\underline { \text { table-level } }$ and column-level approaches to creating a constraint can be included in the same command. _________________________

Question 49

A(n) $\underline { \text { FOREIGN KEY } }$ constraint can only reference a column in the parent table that has been designated as the primary key for that table. _________________________

Question 50

In a "one-to-many" relationship, which constraint is usually added to the "many" table?

A) UNIQUE
B) PRIMARY KEY
C) FOREIGN KEY
D) NOT NULL

Question 51

Which of the following are used to enforce business rules?

A) syntax
B) functions
C) constraints
D) enforcers

Question 52

In the USER_CONSTRAINTS view, the constraint type for a NOT NULL constraint will be listed as $\underline { N }$ _________________________

Question 53

A NOT NULL constraint can only be added to an existing table by using the $\underline { ADD }$ clause with the ALTER TABLE command. _________________________

Question 54

When dropping a(n) $\underline {\text { PRIMARY KEY } }$ constraint, the name of the column does not need to be included in the ALTER TABLE command. _________________________

Question 55

How can constraints be added to a table?

A) as part of the CREATE TABLE command
B) as part of the ALTER TABLE command
C) as part of the PRIMARY KEY command
D) both a and b

Question 56

A(n) $\underline { \text { UNIQUE } }$ constraint will allow NULL values to be stored in the designated column. _________________________

Question 57

The data $\underline { \text { warehouse } }$ contains information about objects included in the database. _________________________

Question 58

The ALTER TABLE command can be used to $\underline { \text { delete } }$ an existing constraint. _________________________

Question 59

The UNIQUE constraint differs from the PRIMARY KEY constraint in what way?

A) The UNIQUE constraint does not allow NULL values.
B) The UNIQUE constraint can be created at either the column level or the table level.
C) The UNIQUE constraint allows NULL values.
D) The UNIQUE constraint ensures that a specific condition is True before a data value is added to a table.

Question 60

The FOREIGN KEY constraint is usually placed on the $\underline { \text { "one" } }$ side of a one-to-many relationship. _________________________

Question 61

When a constraint is created at the table level, the constraint definition is provided ____ the column definition list.

A) before
B) after
C) in the middle of
D) between columns in

Question 62

A PRIMARY KEY that consists of more than one column is called a(n) ____ key.

A) multiple
B) composite
C) comprehensive
D) coherent

Question 63

Which of the following is the standard abbreviation for the constraint NOT NULL?

A) nn
B) nl
C) nv
D) nnv

Question 64

Which of the following statements about the FOREIGN KEY constraint is incorrect?

A) The constraint exists between two tables, called the parent table and the child table.
B) When the constraint exists, by default a record cannot be deleted from the parent table if matching entries exist in the child table.
C) The constraint can reference any column in another table, even a column that has not been designated as the primary key for the referenced table.
D) When the keywords ON DELETE CASCADE are included in the constraint definition, a corresponding child record will automatically be deleted when the parent record is deleted.

Question 65

When used with a FOREIGN KEY, the keyword REFERENCES refers to what?

A) reference integrity
B) relational integrity
C) referential integrity
D) relational constraint

Question 66

Only one ____ constraint can exist for each table.

A) PRIMARY KEY
B) FOREIGN KEY
C) UNIQUE
D) CHECK

Question 67

Constraints are always enforced at the ____ level.

A) table
B) column
C) row
D) database

Question 68

Which of the following statements about creating constraints is incorrect?

A) If you do not provide a name for a constraint, the Oracle11g server will issue an error message.
B) There are two approaches for creating constraints: at the column level or the table level.
C) One industry convention is to use the format tablename_columnname_constraint type for the constraint name.
D) none of the above

Question 69

Which view will display the names of all the constraints that you own?

A) DISPLAY_CONSTRAINTS
B) ALL_CONSTRAINTS
C) USER_CONSTRAINTS
D) TABLE_CONSTRAINTS

Question 70

Which of the following is the standard abbreviation for the constraint FOREIGN KEY?

A) fkey
B) fk
C) fky
D) frk

Question 71

Which keywords identify a column that, if it contains a value, it must match data contained in another table?

A) FOREIGN KEY
B) PRIMARY KEY
C) CHECK
D) UNIQUE

Question 72

Which of the following statements about creating constraints is incorrect?

A) If a constraint applies to more than one column, the constraint must be created at the table level.
B) Using the column level approach, the definition of the constraint is included as part of the column definition.
C) When you create constraints at the column level, the constraint being created applies to the column specified.
D) The NOT NULL constraint can be created at either the column level or the table level.

Question 73

If a constraint applies to more than one column, the constraint must be created at the ____ level.

A) column
B) table
C) row
D) database

Question 74

When a constraint is created at the ____ level with the CREATE TABLE command, the constraint definition is simply included as part of the column definition.

A) table
B) column
C) database
D) row

Question 75

The NOT NULL constraint can only be created at the ____ level.

A) table
B) column
C) database
D) both a and b

Question 76

What is the syntax for the default constraint name provided by the Oracle11g server?

A) SYS_Cn
B) PK_Cn
C) ORA_Cn
D) DEF_Cn

Question 77

Which of the following is not a constraint type in Oracle11g?

A) CHECK
B) UNIQUE
C) NOT NULL
D) REFERENCE

Question 78

A PRIMARY KEY constraint can be added to an existing table by using the ____ clause of the ALTER TABLE command.

A) MODIFY
B) ADD
C) CONSTRAINT
D) none of the above

Question 79

Which of the following types of constraints is used to enforce referential integrity?

A) UNIQUE
B) REFERS
C) FOREIGN KEY
D) CHECK

Question 80

If the ____ keyword is included when a constraint is created, a constraint name must be provided by the user.

A) CONST
B) CONSTRAIN
C) CONSTRAINT
D) none of the above