Deck 11: Group Functions

Question 1

The MAX function can be used with character data.​

Answer 1

True

Question 2

The COUNT function can only be used for numeric columns.​

Answer 2

False

Question 3

Group functions return a group of results per row processed.​

Answer 3

False

Question 4

The SUM function is used to calculate the total amount stored in a numeric field for a group of records.​

Question 5

The GROUP BY clause can only be used when a SELECT statement includes a group function.​

Question 6

Group functions are also known as aggregate functions.​

Question 7

If a group function is used in the WHERE clause,then any individual columns listed in the SELECT clause must also be listed in the GROUP BY clause.​

Question 8

The MIN function can be used with numeric,date,and character columns.​

Question 9

The DISTINCT keyword cannot be used with the MAX function.​

Question 10

The optional UNIQUE keyword instructs Oracle 12c to include only unique numeric values in its calculation.​

Question 11

By default,the AVG function will include NULL values when calculating the average of the numeric values in a specified column.​

Question 12

By default,the SUM function assumes the ALL keyword and the result will include multiple occurrences of numeric values.​

Question 13

The GROUP BY clause is used to group data.​

Question 14

The COUNT(*)function is only used to count the number of records containing NULL values.​

Question 15

AVG,COUNT,and STDDEV are all considered group functions.​

Question 16

The MIN function is used to determine the smallest value in a specified column.​

Question 17

The only group function that includes NULL values by default is the MIN function.​

Question 18

Group functions return one result per group of rows processed.

Question 19

The MAX function can only be used with numeric or date columns.​

Question 20

The COUNT function can be used to count NULL,as well as,non-NULL values.​

Question 21

A grouping sets expression can perform multiple Group BY clauses in a single query.​

Question 22

Pattern matching features available in a SELECT are targeted to analyze patterns or trends of a specific column of data across many rows.​

Question 23

The VARIANCE function is used to determine the variance in a group of numeric data.​

Question 24

​If both nonaggregated and aggregated columns are used in the SELECT clause,the GROUP BY clause must contain the nonaggregated columns.

Question 25

Column aliases can be used in the GROUP BY clause.​

Question 26

The STDVAR function is used to determine the standard deviation of numeric data.​

Question 27

Group functions can only be nested to a depth of two.​

Question 28

A SELECT statement cannot include both a GROUP BY and an ORDER BY clause.​

Question 29

Columns used to group data in the GROUP BY clause must also be listed in the SELECT clause.​

Question 30

SUM,AVG,and COUNT are all considered group functions._________________________​

Question 31

The WHERE clause specifies which groups will be displayed in the results.​

Question 32

The HAVING clause is used to restrict the groups returned by a query.​

Question 33

When the SELECT statement includes both WHERE and GROUP BY clauses,the GROUP BY clause is always evaluated first.​

Question 34

The COUNT(*)function can be used to count the number of rows containing NULL and non-NULL values._________________________​

Question 35

The TOTAL function is used to calculate the total value stored in a numeric field for a group of records._________________________​

Question 36

The optional DISTINCT keyword instructs Oracle12c to include only unique numeric values in the calculation._________________________​

Question 37

The AVG function only includes non-NULL values in its calculations._________________________​

Question 38

The only group function that includes NULL values is the NVL function._________________________​

Question 39

The COUNT function is used to total the values stored in numeric columns._________________________​

Question 40

Single-row functions return one result per group of rows processed._________________________​

Question 41

Functions that return one result per group of rows are called ____ functions.​

A) ​group
B) ​multiple-row
C) ​aggregate
D) ​all of the above

Question 42

The VAR function is used to determine the variance contained within a set of data._________________________​

Question 43

When a SELECT statement includes WHERE,HAVING,and GROUP BY clauses,the GROUP BY clause is always evaluated first._________________________​

Question 44

The ORDER BY clause is used to group data._________________________​

Question 45

The GROUP BY clause is used to restrict the groups returned by a query._________________________​

Question 46

If a group function is used in the SELECT clause,then any individual columns listed in the SELECT clause must also be listed in the ORDER BY clause._________________________​

Question 47

The HAVING clause specifies which groups will be displayed in the results,while the WHERE clause restricts the records that are retrieved from the table for processing._________________________​

Question 48

Columns used to group data in the GROUP BY clause do not have to be listed in the SELECT clause._________________________​

Question 49

Which of the following is not considered a group function?​

A) ​TRUNC
B) ​MIN
C) ​COUNT
D) ​SUM

Question 50

When group functions are nested,the inner function is always resolved first._________________________​

Question 51

By default,the COUNT function uses the DISTINCT keyword when counting the values contained in a column._________________________​

Question 52

The HAVING clause serves as the WHERE clause for aggregated data._________________________​

Question 53

The STDDEV function calculates the standard deviation for the data contained in a specified field._________________________​

Question 54

Group functions can be nested inside single-row functions._________________________​

Question 55

The default keyword for group functions is ____.​

A) ​ALL
B) DISTINCT
C) ​INCLUDENULLS
D) ​NONULLS

Question 56

The WHERE clause can contain group functions._________________________​

Question 57

​The MIN function can be used with the DISTINCT or ALL keywords._________________________

Question 58

The WHERE clause filters the data before grouping,while the HAVING clause filters the groups after grouping is performed._________________________​

Question 59

Results returned from a SELECT statement that include a GROUP BY clause will present the results in descending order of the column(s)listed in the GROUP BY clause._________________________​

Question 60

The MAX functions returns the smallest value stored in the specified column._________________________​

Question 61

Which of the following cannot be used with date columns?​

A) ​MIN
B) ​MAX
C) ​AVG
D) ​all of the above

Question 62

The ____ clause is used to indicate that groups should be created.​

A) ​ORDER BY
B) ​GROUP BY
C) ​AGGREGATED
D) ​GROUPING

Question 63

The ____ function can be used to determine the number of rows containing a specified value.​

A) ​TOTAL
B) ​SUM
C) ​COUNT
D) ​ADD

Question 64

The ____ function can be used to determine the number of rows meeting a specific condition.​

A) ​ADD
B) ​SUM
C) ​COUNT
D) ​TOTAL

Question 65

The ____ clause is used to restrict the groups returned by a query.​

A) ​FROM
B) ​WHERE
C) ​HAVING
D) ​GROUP BY

Question 66

If the DISTINCT keyword is not included in the SUM function,the ____ keyword will be assumed.​

A) ​UNIQUE
B) ​ALL
C) ​RANDOM
D) ​none of the above

Question 67

The ____ function is used to calculate the total amount stored in a numeric field.​

A) ​TOTAL
B) ​SUM
C) ​AVERAGE
D) ​ADD

Question 68

The AVG function can be used with ____ values.​

A) ​numeric
B) ​character
C) ​date
D) ​all of the above

Question 69

The ____ function can be used to determine the largest value stored in a specified column.​

A) ​MAXIMUM
B) ​MAX
C) ​LARGE
D) ​LARGEST

Question 70

The MIN function can be used with ____ columns.​

A) ​numeric
B) ​character
C) ​date
D) ​all of the above

Question 71

The SUM function can only be used with ____ data.​

A) ​numeric
B) ​character
C) ​date
D) ​alphanumeric

Question 72

Which of the following lines of the SQL statement contains an error?
1 SELECT title,MAX(retail)
2 FROM books
3 WHERE retail > 30
4 AND pubid = 1
5 GROUP BY retail

A) ​Line 2
B) ​Line 3
C) ​Line 4
D) ​Line 5

Question 73

If the DISTINCT keyword is not included in the AVG function,the ____ keyword will be assumed.​

A) ​ALL
B) ​UNIQUE
C) ​GROUP
D) ​none of the above

Question 74

The MAX function can be used with which type of columns?​

A) ​numeric
B) ​date
C) ​character
D) ​all of the above

Question 75

If a group function is used in the SELECT clause,any ____ listed in the SELECT clause must also be listed in the GROUP BY clause.​

A) ​aggregate function
B) ​single-row function
C) ​individual column
D) ​all of the above

Question 76

Which of the following is a valid statement?​

A) ​The ORDER BY clause cannot be used in a SELECT statement containing a GROUP BY clause.
B) ​Data returned from a GROUP BY clause will automatically be sorted in descending order.
C) ​Column aliases cannot be used in a GROUP BY clause.
D) ​Columns referenced in the GROUP BY clause must also be contained in the SELECT clause.

Question 77

The ____ function calculates the average of the numeric values in a specified column.​

A) ​AVG
B) ​AVERAGE
C) ​MEAN
D) ​AG

Question 78

Which of the following is a correct statement?​

A) ​An asterisk can be used as the argument for the COUNT function to include NULL values in the results.
B) ​The NULL keyword can be included in the argument of the COUNT function to include NULL values in the results.
C) ​The ALL keyword can be included in the argument of the COUNT function to include NULL values in the results.
D) ​The INCLUDE NULLS keywords can be included in the argument for the COUNT function to include NULL values in the results.

Question 79

The ____ function returns the smallest value in a specified column.​

A) ​LOW
B) ​LOWEST
C) ​MIN
D) ​MINIMUM

Question 80

The ____ function can be used to include NULL values in a calculation.​

A) ​AVG
B) ​SUM
C) ​NULL
D) ​NVL