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databases Online Quiz - 10

Description: databases Online Quiz - 10
Number of Questions: 20
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Tags: databases
Attempted 0/20 Correct 0 Score 0

What is true about MERGE command? Choose all that apply.

  1. It is a DML command

  2. It is a DDL command

  3. Provides the ability to conditionally update or insert data into a database table

  4. Provides the ability to MERGE VIEWS and INDICES of a TABLE


Correct Option: A,C

Select TYPES of JOINS. Choose all that apply.

  1. EQUI-JOIN

  2. NONEQUI-JOIN

  3. SELF-JOIN

  4. OUTER-JOIN

  5. MERGE-JOIN

  6. TRANSACTION-JOIN


Correct Option: A,B,C,D

AI Explanation

To answer this question, let's go through each option to understand why it is correct or incorrect:

Option A) EQUI-JOIN - This option is correct. An EQUI-JOIN is used to combine rows from two or more tables based on a related column between them.

Option B) NONEQUI-JOIN - This option is correct. A NONEQUI-JOIN is used to combine rows from two or more tables based on a condition that is not an equality.

Option C) SELF-JOIN - This option is correct. A SELF-JOIN is used to join a table to itself, treating it as two separate tables.

Option D) OUTER-JOIN - This option is correct. An OUTER-JOIN is used to combine rows from two or more tables, including unmatched rows from one or both tables.

Option E) MERGE-JOIN - This option is incorrect. A MERGE-JOIN is not a type of join. It is a technique used in query optimization to merge sorted data sets.

Option F) TRANSACTION-JOIN - This option is incorrect. A TRANSACTION-JOIN is not a type of join. It does not exist in the context of SQL joins.

The correct answer is A, B, C, and D. These options are correct because they represent different types of joins commonly used in SQL queries.

Choose the MANDATORY clauses of SELECT SQL statement

  1. SELECT

  2. WHERE

  3. GROUP BY

  4. FROM

  5. ORDER BY

  6. HAVING


Correct Option: A,D

ALIAS can be used for TABLE as well as COLUMN to simplify interpretation of SQL query

  1. True

  2. False


Correct Option: A

Identify the correct output select INITCAP('ORACLE BASICS') from dual;

  1. ORACLE BASICS

  2. Oracle Basics

  3. oracle basics

  4. oracleBasics


Correct Option: B

Identify the correct output --- select CONCAT('ORACLE' || 'BASICS') from dual;

  1. ORACLE BASICS

  2. ORACLEBASICS

  3. oraclebasics

  4. oracleBasics


Correct Option: B

Identify the correct output --- select SUBSTR('ORACLE BASICS',-6,5) from dual;

  1. BASIC

  2. BASICS

  3. E BAS

  4. ORACL


Correct Option: A

Identify the correct output --- select TRUNC(TO_DATE('01-SEP-1995', 'DD-MON-YYYY'),'YEAR') from dual;

  1. 01-SEP-1995

  2. 01-JAN-1995

  3. 01-JAN-1996

  4. 1995

  5. 1996


Correct Option: B

Identify the correct output --- select ADD_MONTHS(TO_DATE('01-SEP-1995', 'DD-MON-YYYY'), 6) from dual;

  1. 01-MAR-1996

  2. 01-FEB-1996

  3. 07-SEP-1995

  4. 06-SEP-1995


Correct Option: A

Which functions mentioned below are GROUP functions? Choose all that apply

  1. ADD_MONTHS

  2. COUNT

  3. ROUND

  4. DISTINCT

  5. AVG

  6. SUM


Correct Option: B,E,F
  1. WHERE clause

  2. GROUP BY clause

  3. GROUP functions

  4. DISTINCT keyword

  5. FROM clause


Correct Option: B,C,D

Identify the MANDATORY sections of a PL/SQL block

  1. DECLARE

  2. BEGIN

  3. EXCEPTION

  4. END


Correct Option: B,D

INSERT, UPDATE, DELETE commands when used in a PL/SQL block, should contain INTO clause to hold the data returned by SQL statement

  1. True

  2. False


Correct Option: B

IF-THEN-ELSE-ENDIF construct is used for conditional control in a PL/SQL block. What happens if the condition in IF-THEN-ELSE-ENDIF block evaluates to NULL?

  1. The SQL statements in the IF condition are processed.

  2. The SQL statements in the ELSE condition are processed.

  3. IF-THEN-ELSE-ENDIF construct is skipped.

  4. The SQL statements in the IF condition as well as ELSE condition are processed.


Correct Option: C

Identify the ITERATIVE control constructs in PL/SQL. Choose all that apply

  1. Cursors

  2. Cursor For Loop

  3. Simple Loop

  4. Exit Loop

  5. Numeric For Loop

  6. While Loop


Correct Option: B,C,E,F
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