mysql count unique row values

Question

TABLE quotation

id  clientid
1   25
2   25
3   25
4   25
5   26

How can I query how many different clients exist in TABLE qu

Answer 1

If you want to count the total number of unique entries this will return a number in column count.

SELECT COUNT(*) as total FROM (SELECT COUNT(*) FROM quotation GROUP BY clientid having count(*) > 1) t1

If you want to count the total number of entries with duplicate rows then use the following mysql.

SELECT COUNT(*) as total FROM (SELECT COUNT(*) FROM quotation GROUP BY clientid having count(*) >= 2) t1