Wilco Placement Paper -: SQL Questions And Answers

Wilco Previous Years Solved Sample Placement Papers

1. What should be done when a left parenthesis ‘(‘ is encountered?

   a) It is ignored

   b) It is placed in the output

   c) It is placed in the operator stack

   d) The contents of the operator stack is emptied

   Answer: c

   Explanation: When a left parenthesis is encountered, it is placed on to the operator stack. When the corresponding right parenthesis is encountered, the stack is popped until the left parenthesis and remove both the parenthesis.

2. What will be the output of the program?

   #include
   struct course
   {
       int courseno;
       char coursename[25];
   };
   int main()
   {
       struct course c[] = { {102, “Java”},
                             {103, “PHP”},
                             {104, “DotNet”} };
       printf(“%d”, c[1].courseno);
       printf(“%s\n”, (*(c+2)).coursename);
       return 0;
   }
       

   A. 103 Dotnet

   B. 102 Java

   C. 103 PHP

   D. 104 DotNet

   Ans: A

3. Which prefixes are available to Oracle triggers?

   A. :new only

   B. :old only

   C. Both :new and :old Answer: Option C

   D. Neither :new nor :old

4. Solution: Oracle triggers can use both the :new and :old prefixes to refer to the new and old values of a record.

5. What Oracle backup and recovery file contains user and system data?

   A. Control file

   B. Datafile Answer: Option B

   C. OnLine ReDo file

   D. Offline ReDo file

6. Solution: A datafile in Oracle contains user and system data.

7. What is the type of Oracle backup in which all uncommitted changes have been removed from the datafiles?

   A. Full backup

   B. Consistent backup Answer: Option B

   C. Inconsistent backup

   D. Differential backup

8. Solution: A consistent backup in Oracle is one in which all uncommitted changes have been removed from the datafiles.

9. Composition is a stronger form of which of the following?

   A. Aggregation Answer: Option A

   B. Encapsulation

   C. Inheritance

   D. All of the above

10. Solution: Composition is a stronger form of aggregation.

11. Which SQL-92 standard SQL command can be used to change a table name?

    A. RENAME TABLE

    B. CHANGE TABLE

    C. ALTER TABLE

    D. None of the above is correct Answer: Option D

12. Solution: There is no SQL-92 standard SQL command specifically to change a table name.

13. Changing cardinalities in a database is:

    A. a common database design task Answer: Option A

    B. a rare database design task, but does occur

    C. a database design task that never occurs

    D. is impossible to do, so a new database must be constructed and the data moved into it

14. Solution: Changing cardinalities in a database is a common database design task.

15. If a denormalization situation exists with a many-to-many or associative binary relationship, which of the following is true?

    A. All fields are stored in one relation

    B. All fields are stored in two relations Answer: Option B

    C. All fields are stored in three relations

    D. All fields are stored in four relations

16. Solution: If a denormalization situation exists with a many-to-many or associative binary relationship, all fields are stored in two relations.

17. In the question below a sentence broken into five or six parts. Join these parts to make a meaningful sentence. The correct order of parts is the answer.

    1. of

    2. we

    3. Heard

    4. him

    5. had

    A. 42351

    B. 52341

    C. 25341

    D. 25431

    E. 25314 Answer: Option E

18. Solution: The correct order of parts is 25314, making the sentence "We had heard of him".

19. In the question below a sentence broken into five or six parts. Join these parts to make a meaningful sentence. The correct order of parts is the answer.

    1. not

    2. Hari

    3. Away

    4. run

    5. did

    A. 13542

    B. 35412

    C. 52431

    D. 25143 Answer: Option D

    E. 21345

20. Solution: The correct order of parts is 25143, making the sentence "Hari did not run away".

21. In questions below, a part of the sentence is italicised and underlined. Below are given alternatives to the italicised part which may improve the sentence. Choose the correct alternative

    his powerful desire brought about his downfall.

    A. His intense desire

    B. His desire for power Answer: Option B

    C. His fatal desire

    D. No improvement

22. Solution: The correct alternative is "His desire for power".

23. In questions below, a part of the sentence is italicised and underlined. Below are given alternatives to the italicised part which may improve the sentence. Choose the correct alternative

    The logic of Berlin wall already had been undermined but when the news came through that the wall itself had been opened I jumped into a car.

    A. had been undetermined already

    B. had already been undetermined Answer: Option B

    C. had been already undetermined

    D. No improvement

24. Solution: The correct alternative is "had already been undetermined".