DBMS MCQ's Question Set 1
Q.1. A relational database consists of a collection of
- Tables
- Fields
- Records
- Keys
Answer:- (1)
Q.2. Database __________ which is the logical design of the database, and the database _______ which is a snapshot of the data in the database at a given instant in time.
- Instance, Schema
- Relation, Schema
- Relation, Domain
- Schema, Instance
Answer:- (4)
Q.3. A domain is atomic if elements of the domain are considered to be ____________ units.
- Different
- Indivisbile
- Constant
- Divisible
Answer:- (2)
Q.4. Which one of the following is a set of one or more attributes taken collectively to uniquely identify a record?
- Candidate key
- Sub key
- Super key
- Foreign key
Answer:- (3)
Q.5. The subset of a super key is a candidate key under what condition?
- No proper subset is a super key
- All subsets are super keys
- Subset is a super key
- Each subset is a super key
Answer:- (1)
Q.6. The relation with the attribute which is the primary key is referenced in another relation. The relation which has the attribute as a primary key is called
- Referential relation
- Referencing relation
- Referenced relation
- Referred relation
Answer:- (2)
Q.7. The ______ is the one in which the primary key of one relation is used as a normal attribute in another relation.
- Referential relation
- Referencing relation
- Referenced relation
- Referred relation
Answer:- (3)
Q.8. Using which language can a user request information from a database?
- Query
- Relational
- Structural
- Compiler
Answer:- (1)
Q.9. Which one of the following is used to define the structure of the relation, deleting relations and relating schemas?
- DML(Data Manipulation Langauge)
- DDL(Data Definition Langauge)
- Query
- Relational Schema
Answer:- (2)
Q.10. Updates that violate __________ are disallowed.
- Integrity constraints
- Transaction control
- Authorization
- DDL constraints
Answer:- (1)
Q.11. This Query can be replaced by which one of the following?
SELECT name, course_id
FROM instructor, teaches
WHERE instructor_ID= teaches_ID; |
- Select name,course_id from teaches,instructor where instructor_id=course_id;
- Select name, course_id from instructor natural join teaches;
- Select name, course_id from instructor;
- Select course_id from instructor join teaches;
Answer:- (2)
Q.12. Which of the following statements contains an error?
- Select * from emp where empid = 10003;
- Select empid from emp where empid = 10006;
- Select empid from emp;
- Select empid where empid = 1009 and lastname = ‘GELLER’;
Answer:- (4)
Q.13. By default, the order by clause lists items in ______ order.
SELECT name
FROM instructor
WHERE dept name = ’Physics’
ORDER BY name;
|
- Descending
- Any
- Same
- Ascending
Answer:- (4)
Q.14. The number of attributes in relation is called as its
- Cardinality
- Degree
- Tuples
- Entity
Answer:- (2)
Q.15. _________ joins are SQL server default
- Outer
- Inner
- Equi
- None of the mentioned
Answer:- (2)
Q.16. The predicate in a where clause can involve Boolean operations such as and. The result of true and unknown is_______ false and unknown is _____ while unknown and unknown is _____
- Unknown, unknown, false
- True, false, unknown
- True, unknown, unknown
- Unknown, false, unknown
Answer:- (4)
Q.17. Some of these insert statements will produce an error. Identify the statement.
CREATE TABLE employee (id INTEGER,name VARCHAR(20),salary NOT NULL);
INSERT INTO employee VALUES (1005,Rach,0);
INSERT INTO employee VALUES (1007,Ross, );
INSERT INTO employee VALUES (1002,Joey,335);
|
- Insert into employee values (1005,Rach,0);
- Insert into employee values (1002,Joey,335);
- Insert into employee values (1007,Ross, );
- None of the mentioned
Answer:- (3)
Q.18. Aggregate functions are functions that take a ___________ as input and return a single value.
- Collection of values
- Single value
- Aggregate value
- Both Collection of values & Single value
Answer:- (1)
Q.19. Aggregate functions can be used in the select list or the_______clause of a select statement or subquery. They cannot be used in a ______ clause.
- Where, having
- Having, where
- Group by, having
- Group by, where
Answer:- (2)
Q.20. How can you find rows that do not match some specified condition?
- EXISTS
- Double use of NOT EXISTS
- NOT EXISTS
- None of the mentioned
Answer:- (2)
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