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Multiple Choice Questions - SQL EXISTS and IN

Multiple Choice Questions - SQL EXISTS and IN

1. While using the IN operator, the SQL engine will scan all records fetched from the inner query.

A) True
B) False

2. Consider the below table.

Table tab_1:
IDColumn_2Name
11F1Fardeen
22 G1 Gautam
33 H1 Harish
44 I1 Fardeen
55 E1 Eklavya
NULL NULL NULL
0 0 0

What is the result of the below query:

select * from tab_1
where '0' in (select ID from Tab_1 where ID in (0))

A)
IDColumn_2Name
0 0 0

B)
IDColumn_2Name
NULL NULL NULL

C)
IDColumn_2Name
11F1Fardeen
22 G1 Gautam
33 H1 Harish
44 I1 Fardeen
55 E1 Eklavya
NULL NULL NULL
0 0 0

D)
None of above

3. The select list of a subquery introduced by EXISTS almost always consists of ………. There is no reason to list column names as you are just verifying whether rows that meet the conditions specified in the subquery exist.

A) percent (%)
B) asterisk (*)
C) Comma (,)
D) None of above

4. Only EXISTS can be prefixed with NOT but IN cannot be.

A) True
B) False

5. When EXISTS is used, SQL Server stops as soon as it finds .......... record that matches the criteria.

A) Middle
B) Last
C) One
D) None of above

6. NOT EXISTS works like EXISTS, except the WHERE clause in which it is used is satisfied if ........... rows are returned by the subquery.

A) Two
B) Unpinned
C) TOP
D) No

7. The keyword EXISTS is not preceded by a ............

A) constant
B) column name
C) other expression
D) All of above

8. Consider the below table.

Table dbo.tab_1
IDColumn_2Name
11F1Fardeen
22 G1 Gautam
33 H1 Harish
44 I1 Fardeen
55 E1 Eklavya

What is the result of the below query:

DECLARE @InList varchar(100)
SET @InList = '11,12,33,44'

SELECT *
FROM Tab_1
WHERE ','+@InList+',' LIKE ',%'+CAST(Id AS varchar)+',%'

A)
IDColumn_2Name
11F1Fardeen
33 H1 Harish
44 I1 Fardeen

B)
IDColumn_2Name
11F1Fardeen
22 G1 Gautam
33 H1 Harish
44 I1 Fardeen

C)
IDColumn_2Name
11F1Fardeen
22 G1 Gautam
33 H1 Harish
44 I1 Fardeen
55 E1 Eklavya

D) None of above

9. Consider the below table.

Table tab_1
IDColumn_2Name
11F1Fardeen
22 G1 Gautam
33 H1 Harish
44 I1 Fardeen
55 E1 Eklavya
NULL NULL NULL

What will be the result of following query:

SELECT ID, column_2, Name
FROM dbo.tab_1
WHERE EXISTS (SELECT NULL)

A)
IDColumn_2Name
11F1Fardeen
22 G1 Gautam
33 H1 Harish
44 I1 Fardeen
55 E1 Eklavya

B) It will show an error message.

C)
IDColumn_2Name
NULL NULL NULL

D)
IDColumn_2Name
11F1Fardeen
22 G1 Gautam
33 H1 Harish
44 I1 Fardeen
55 E1 Eklavya
NULL NULL NULL


10. Exists uses a ............ to join values from a column to a column within the subquery.

A) View
B) Join
C) Subquery
D) Clustered Index



Answers