Question

QUESTION 26

1. For more efficient SQL, replace a series of OR clauses with

   		IN
   		AND
   		NULL
   		DISTINCT

2.5 points   

QUESTION 27

1. SELECT ADD_MONTHS('01-FEB_2016', 3) from dual; results in

   		04-FEB-2016
   		01-MAY-2016
   		31-MAY-2016
   		04-MAY-2016

2.5 points   

QUESTION 28

1. joining a table to itself is refered to as

   		an equijoin
   		a self join
   		an outer join
   		a non equi-join

2.5 points   

QUESTION 29

1. SELECT MIN(NAME) from Customer; will return which of the following rows

   		ALICE
   		WILLIAM
   		BLAKE
   		JAMAL

2.5 points   

QUESTION 30

1. To obtain all the rows from two tables regardless of matches which join should be used

   		RIGHT OUTER
   		LEFT OUTER
   		EQUIJOIN
   		FULL OUTER

2.5 points   

QUESTION 31

1. To sort data returned from a SQL statement, which clause should be used

   		ORDER BY
   		WHERE
   		GROUP BY
   		HAVING

Its a multiple question answer.I donot have any more database

Answer 1

Question 26:

For more efficient SQL, replace a series of OR clauses with IN

The correct option is a) IN

Explanation:

OR can be replaced with IN considering MySQL as your RDBMS.

For e.g. given a query

Version1

SELECT * FROM table1 WHERE item_desc = 'item 1' OR item_desc = 'item 2'

can be replaced with

Version2

SELECT * FROM table1 WHERE item_desc IN ('item 1','item 2')

The queries given in Version1 and Version2 will give the same result.

Question 27:

SELECT ADD_MONTHS (01-FEB-2016’,3) FROM DUAL; results in 01-MAY-2016.

The correct option is b) 01-MAY-2016

Explanation: The function ADD_MONTHS () is used to add the required number of months to the date and result the output. The first argument of the function ADD_MONTHS () is the date and the second argument is the required number of months which should be added to the date.

Question 28:

Joining a table to itself is referred to as a self-join.

The correct option is b) self-join

Explanation: In self-join, the table is joined with itself. The table is joined with itself such that it appears that they are two tables. At least one table is temporarily renamed.

Question 29:

The given query will give that name as output which has the minimum length. Here, the length of the names is as follows:

ALICE – 5

WILLIAM-7

BLAKE – 5

JAMAL – 5

Here, the length of ALICE, BLAKE and JAMAL is the same and it is the minimum

So, the correct options will be a), c), d)

Question 30:

To obtain all the rows from two tables regardless of matches, FULL JOIN should be used.

The correct option is d) FULL OUTER

Explanation: The FULL OUTER join is the type of join which returns all the records which means all the rows from both the tables. In case the join condition is not met, for any rows on either side of the join, the columns for the other table have NULL values for that row.

Question 31:

To sort data returned from a SQL statement, ORDER BY clause should be used.

The correct option is a) ORDER BY

Explanation: The ORDER BY clause is used to sort in ascending or descending order based on single or multiple columns.