Relational Database Design Set 1 MCQs

Q1 | An attribute is a __________ in a relation.

Row

Column

Value

Tuple

Q2 | What is the method of specifying a primary key in a schema description?

By writing it in bold letters

By underlining it using a dashed line

By writing it in capital letters

By underlining it using a bold line

Q3 | Choose the option that correctly explains in words, the function of the following relationalalgebra expression σyear≥2009 (book ⋈ borrow)

Selects all tuples from the Cartesian product of book and borrow

Selects all the tuples from the natural join of book and borrow wherever the year is lesser than 2009

Selects all the tuples from the natural join of book and student wherever the year is greater than or equal to 2009

Selects all tuples from the Cartesian product of book and borrow wherever the year is greater than or equal to 2009

Q4 | State true or false: If a relation consists of a foreign key, then it is called a referencedrelation of the foreign key dependency.

True

False

none

all

Q5 | Statement 1: A tuple is a row in a relationStatement 2: Existence of multiple foreign keys in a same relation is possible

Both the statements are true

Statement 1 is correct but Statement 2 is false

Statement 1 is false but Statement 2 is correct

Both the statements are false

Q6 | Which of the following information does an SQL DDL not specify?

The schema for each relation

The integrity constraints

The operations on the tuples

The security and authorization information for each relation

Q7 | Which of the following data types does the SQL standard not support?

char(n)

String(n)

varchar(n)

float(n)

Q8 | Which command is used to create a new relation in SQL

create table( , …)

create relation( , …)

new table( , …)

new relation( , …)

Q9 | If a1, a2, a3 are attributes in a relation and S is another relation, which of the following isan incorrect specification of an integrity constraint?

primary key(a1, a2, a3)

primary key(a1)

foreign key(a1, a2) references S

foreign key(a1, a2)

Q10 | What is the syntax to load data into the database? (Consider D as the database and a, b, cas datA:)

enter into D (a, b, C:);

insert into D values (a, b, C:);

insert into D (a, b, C:);

insert (a, b, C:) values into D;

Q11 | Which of the following commands do we use to delete a relation (R) from a database?

drop table R

drop relation R

delete table R

delete from R

Q12 | Which of the following commands do we use to delete all the tuples from a relation (R)?

delete table R

drop table R

delete from R

drop from R

Q13 | Choose the correct command to delete an attribute A from a relation R

alter table R delete A

alter table R drop A

alter table drop A from R

delete A from R

Q14 | create table apartment(ownerID varchar (5), ownername varchar(25), floor numeric(4,0),primary key (ownerID:));Choose the correct option regarding the above statement

The statement is syntactically wrong

It creates a relation with three attributes ownerID, ownername, floor in which floor cannot be null.

It creates a relation with three attributes ownerID, ownername, floor in which ownerID cannot be null.

It creates a relation with three attributes ownerID, ownername, floor in which ownername must consist of at least 25 characters.

Q15 | What does the notnull integrity constraint do?

It ensures that at least one tuple is present in the relation

It ensures that at least one foreign key is present in the relation

It ensures that all tuples have a finite value on a specified attribute

It ensures that all tuples have finite attributes on all the relations

Q16 | Which SQL function is used to count the number of rows in a SQL query?

COUNT()

NUMBER()

SUM()

COUNT(*)

Q17 | Which SQL keyword is used to retrieve a maximum value?

MOST

TOP

MAX

UPPER

Q18 | Which of the following SQL clauses is used to DELETE tuples from a database table?

DELETE

REMOVE

DROP

CLEAR

Q19 | ___________removes all rows from a table without logging the individual row deletions.

DELETE

REMOVE

DROP

TRUNCATE

Q20 | Which of the following is not a DDL command?

UPDATE

TRUNCATE

ALTER

None of the Mentioned

Q21 | Which of the following are TCL commands?

UPDATE and TRUNCATE

SELECT and INSERT

GRANT and REVOKE

ROLLBACK and SAVEPOINT

Q22 | ________________ is not a category of SQL command.

TCL

SCL

DCL

DDL

Q23 | If you don’t specify ASC or DESC after a SQL ORDER BY clause, the following is usedby default ______________

ASC

DESC

There is no default value

None of the mentioned

Q24 | Which of the following statement is true?

DELETE does not free the space containing the table and TRUNCATE free the space containing the table

Both DELETE and TRUNCATE free the space containing the table

Both DELETE and TRUNCATE does not free the space containing the table

DELETE free the space containing the table and TRUNCATE does not free the space containing the table

Q25 | What is the purpose of the SQL AS clause?

The AS SQL clause is used to change the name of a column in the result set or to assign a name to a derived column

The AS clause is used with the JOIN clause only

The AS clause defines a search condition

All of the mentioned