SQL Functions

Question 1

What is an Aggregating function?

Answer 1

An aggregating function takes a list of values and returns just one value

Question 2

Name the Aggregating Functions

Answer 2

SUM, COUNT, MAX, MIN, ROUND, AVG

Question 3

What does the ORDER BY function do?

Answer 3

The ORDER BY causes orders or sorts a result based on the values in one or more specific columns.

Question 4

What does the GROUP BY function do?

Answer 4

Divides the rows in a table into smaller groups

Question 5

What clause can be used to filter rows BEFORE aggregation?

Answer 5

The WHERE clause

Question 6

What clause can be used to filter rows AFTER aggregation?

Answer 6

The HAVING clause

Question 7

What does the LEFT() function do?

Answer 7

Returns the leftmost characters from the string

Question 8

What is a CASE statement used for?

Answer 8

You can use a CASE statement to put values into categories

Question 9

What does the COALESCE function do?

Answer 9

Returns the first non-NULL value in the list, or NULL if there are no non-NULL values.

Question 10

What does a Null value indicate?

Answer 10

an unknown value or “not applicable”