This set of RDBMS Questions and Answers for Freshers focuses on “Sql Data Types and Schemas”.
1. Which of the following is not a valid Date and Time data type?
Explanation: datestamp is not a valid Date and Time data type. Timestamp exists but datestamp does not exist in SQL.
2. What is a timestamp?
a) A combination of date and time with date first
b) A combination of date and time with time first
c) A combination of time and place with time first
d) A combination of time and place with place first
Explanation: A timestamp is a combination of date and time with date first.
Eg: ‘2002-04-25 10:20:04.43’.
3. What does p indicate in the following data type?
a) The amount of delay that needs to be added to the time
b) The number of fractional digits for the seconds
c) The maximum number of allowed hours
d) None of the mentioned
Explanation: The p in the parentheses indicates the number of fractional digits for seconds.
4. What is a default value?
a) It is a value that automatically creates a primary key
b) It is a value that cannot be altered during insertion of values in the tuple
c) It is a value that is initially loaded into the attribute
d) None of the mentioned
Explanation: A default value is a value that is initially loaded into the attribute. All the tuples have the default value in the attribute for which it is specified in case any value is not externally specified.
5. Which of the following is an illegal data type in SQL
Explanation: clob and blob are called large object data types. They can be used to store values that can go to the size of gigabytes. Number is used to store the basic integer data type.
6. State true or false: Users can define new data types in SQL
Explanation: SQL allows the creation of new data types using the “create type
7. What does the following statement do?
create table temp_inst like institute
a) It creates a new relation temp_inst with all the tuples and attributes of the institute relation
b) It creates a new relation temp_inst with the same schema as that of the institute relation
c) It creates a new relation named temp_inst with institute as its only attribute
d) It does not create any relations and returns an error
Explanation: The create table like statement creates a new relation which has a schema identical to that of the specified relation after the like keyword.
8. Which of the following is a privilege in SQL standard?
d) All of the mentioned
Explanation: The SQL standard includes the privileges select, insert, update and delete. This privilege set can be granted or revoked among the users.
9. The _________ statement is used in SQL to confer authorization.
Explanation: The grant statement is used in SQL to confer authorization. It has the syntax
grant <privileges> on <relation name> to <user list>;
10. revoke select on takes from amit;
What does the above query perform?
a) It revokes all authorizations from amit
b) It revokes select authorization from amit
c) It revokes takes authorization from amit
d) It gives an error
Explanation: The query mentions the revoking of the select privilege. So, the query revokes the select authorization from amit.
Sanfoundry Global Education & Learning Series – RDBMS.
To practice all areas of RDBMS for Freshers, here is complete set of 1000+ Multiple Choice Questions and Answers.