Question

Choose all the optional query block in “Select “retrieval query?

	A.	Select
	B.	Where
	C.	From
	D.	Order By

A NULL value means

	A.	Value missing
	B.	Value unknown
	C.	More than 1000
	D.	All the above

Delete from DEF; /*DEF is a table/relation*/

What action does this command perform?

	A.	Delete the table
	B.	Delete all the rows from the table
	C.	Deletes a column
	D.	Deletes the top 10 tuples

A attribute/column, fName, is of Data Type varchar(100). One of entries is “ABC”.

How many spaces does the entry of this value  creates?

	A.	0
	B.	100
	C.	103
	D.	97

Which of the following Join operation will give only the matching tuples?

	A.	Inner Join
	B.	Left Outer Join
	C.	Right Outer Join
	D.	Full Outer Join

Answer 1

Question:

Choose all the optional query block in “Select “retrieval query?
Answer:
Where and Order By

Explanation:

Both where as well as Order By arec optional in a SELECT query

Question:

A NULL value means
Answer:
Value missing

Explanation:

Null value means thatv there is no value inserted in that field

Question:

Delete from DEF; /*DEF is a table/relation*/
What action does this command perform?
Answer:  
Delete all the rows from the table

Explanation:

Simply using delete command on a tabble using from class willl remove all the records from the table ie rows will be deleted

Question:

A attribute/column, fName, is of Data Type varchar(100). One of entries is “ABC”.
How many spaces does the entry of this value creates?
Answer:
0

Explanation:

When varchar is used the data will be stored simply and no spaces will be created.

Question:

Which of the following Join operation will give only the matching tuples?
Answer:
Inner Join

Explanation:

Inner join only produces the tuples that matches the given criteria