COUNT

Returns the number of rows matching the query criteria.

SELECT COUNT(*) FROM PullRequests WHERE State = 'OPEN'

COUNT(DISTINCT)

Returns the number of distinct, non-null field values matching the query criteria.

SELECT COUNT(DISTINCT Title) AS DistinctValues FROM PullRequests WHERE State = 'OPEN'

AVG

Returns the average of the column values.

SELECT State, AVG(AnnualRevenue) FROM PullRequests WHERE State = 'OPEN'  GROUP BY State

MIN

Returns the minimum column value.

SELECT MIN(AnnualRevenue), State FROM PullRequests WHERE State = 'OPEN' GROUP BY State

MAX

Returns the maximum column value.

SELECT State, MAX(AnnualRevenue) FROM PullRequests WHERE State = 'OPEN' GROUP BY State

SUM

Returns the total sum of the column values.

SELECT SUM(AnnualRevenue) FROM PullRequests WHERE State = 'OPEN'