COUNT

Returns the number of rows matching the query criteria.

SELECT COUNT(*) FROM res_users WHERE company_name = 'Company Inc.'

COUNT(DISTINCT)

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

SELECT COUNT(DISTINCT name) AS DistinctValues FROM res_users WHERE company_name = 'Company Inc.'

AVG

Returns the average of the column values.

SELECT email, AVG(meeting_count) FROM res_users WHERE company_name = 'Company Inc.'  GROUP BY email

MIN

Returns the minimum column value.

SELECT MIN(meeting_count), email FROM res_users WHERE company_name = 'Company Inc.' GROUP BY email

MAX

Returns the maximum column value.

SELECT email, MAX(meeting_count) FROM res_users WHERE company_name = 'Company Inc.' GROUP BY email

SUM

Returns the total sum of the column values.

SELECT SUM(meeting_count) FROM res_users WHERE company_name = 'Company Inc.'