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

Try the following statement:

select  distinct A.[Tag],
     count(A.[Tag]) as TAG_COUNT,
     (SELECT count(*) FROM [TagTbl] AS B WHERE A.[Tag]=B.[Tag] AND B.[ID]>0)
     from [TagTbl] AS A GROUP BY A.[Tag]

The first field will be the tag the second will be the whole count the third will be the positive ones count.