COUNT DISTINCT with CONDITIONS

Question

I want to count the number of distinct items in a column subject to a certain condition, for example if the table is like this:

tag | entryID
----+---------
         


        

Answer 1

This may work:

SELECT Count(tag) AS 'Tag Count'
FROM Table
GROUP BY tag

and

SELECT Count(tag) AS 'Negative Tag Count'
FROM Table
WHERE entryID > 0
GROUP BY tag