SQL Server Questions and Answers – Aggregation of Data

This set of SQL Server Multiple Choice Questions & Answers (MCQs) focuses on “Aggregation of Data”.

1. Aggregate functions are functions that take a ___________ as input and return a single value.
a) Collection of values
b) Single value
c) Double value
d) All of the mentioned
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2. SQL applies predicates in the _______ clause after groups have been formed, so aggregate functions may be used.
a) Group by
b) With
c) Where
d) Having
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3. The ________ keyword is used to access attributes of preceding tables or subqueries in the from clause.
a) In
b) Lateral
c) Having
d) With
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4. Which of the following is not an aggregate function?
a) Avg
b) Sum
c) With
d) Min
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5. If we do want to eliminate duplicates, we use the keyword __________in the aggregate expression.
a) Distinct
b) Count
c) Avg
d) Primary key
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6. All aggregate functions except __________ ignore null values in their input collection.
a) Count(attribute)
b) Count(*)
c) Avg
d) Sum
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7. A Boolean data type that can take values true, false, and ____________
a) 1
b) 0
c) Null
d) Unknown
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8. Which of the following should be used to find all the courses taught in the Fall 2009 semester but not in the Spring 2010 semester?
a)

SELECT DISTINCT course id 
FROM SECTION
WHERE semester = ’Fall’ AND YEAR= 2009 AND 
course id NOT IN (SELECT course id FROM SECTION WHERE semester = ’Spring’ AND YEAR= 2010);

b)

SELECT DISTINCT course_id
FROM instructor
WHERE name NOT IN (’Fall’, ’Spring’);

c)

SELECT course id
FROM SECTION
WHERE semester = 'Spring' AND YEAR= 2010);

d)

SELECT COUNT (DISTINCT ID)
FROM takes
WHERE (course id, sec id, semester, YEAR) IN (SELECT course id, sec id, semester, YEAR
FROM teaches
WHERE teaches.ID= 10101);

9. The phrase “greater than at least one” is represented in SQL by ___________
a) < all
b) < some
c) > all
d) > some
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10. We can test for the nonexistence of tuples in a subquery by using the __________ construct.
a) Not exist
b) Not exists
c) Exists
d) Exist
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Sanfoundry Global Education & Learning Series – SQL Server.

To practice all areas of SQL Server, here is complete set of 1000+ Multiple Choice Questions and Answers.