Introduction To Sql(Computer Science > Database ) Questions and answers for exam Preparation

Question 1. You can add a row using SQL in a database with which of the following?

ADD
CREATE
INSERT
MAKE

Explanation:-

Answer: Option C. -> INSERT

Question 2. The command to remove rows from a table 'CUSTOMER' is:

REMOVE FROM CUSTOMER ...
DROP FROM CUSTOMER ...
DELETE FROM CUSTOMER WHERE ...
UPDATE FROM CUSTOMER ...

Explanation:-

Answer: Option C. -> DELETE FROM CUSTOMER WHERE ...

Question 3. Which of the following is the original purpose of SQL?

To specify the syntax and semantics of SQL data definition language
To specify the syntax and semantics of SQL manipulation language
To define the data structures
All of the above

Explanation:-

Answer: Option D. -> All of the above

Question 4. The SQL WHERE clause:

limits the column data that are returned.
limits the row data are returned.
Both A and B are correct.
Neither A nor B are correct.

Explanation:-

Answer: Option B. -> limits the row data are returned.

Question 5. The wildcard in a WHERE clause is useful when?

An exact match is necessary in a SELECT statement.
An exact match is not possible in a SELECT statement.
An exact match is necessary in a CREATE statement.
An exact match is not possible in a CREATE statement.

Explanation:-

Answer: Option B. -> An exact match is not possible in a SELECT statement.

Question 6. A view is which of the following?

A virtual table that can be accessed via SQL commands
A virtual table that cannot be accessed via SQL commands
A base table that can be accessed via SQL commands
A base table that cannot be accessed via SQL commands

Explanation:-

Answer: Option A. -> A virtual table that can be accessed via SQL commands

Question 7. The command to eliminate a table from a database is:

REMOVE TABLE CUSTOMER;
DROP TABLE CUSTOMER;
DELETE TABLE CUSTOMER;
UPDATE TABLE CUSTOMER;

Explanation:-

Answer: Option B. -> DROP TABLE CUSTOMER;

Question 8. ON UPDATE CASCADE ensures which of the following?

Normalization
Data Integrity
Materialized Views
All of the above

Explanation:-

Answer: Option B. -> Data Integrity

Question 9. SQL data definition commands make up a(n) ________ .

DDL
DML
HTML
XML

Explanation:-

Answer: Option A. -> DDL

Question 10. Which of the following is valid SQL for an Index?

CREATE INDEX ID;
CHANGE INDEX ID;
ADD INDEX ID;
REMOVE INDEX ID;

Explanation:-

Answer: Option A. -> CREATE INDEX ID;