Sum of one column group by date column

What if you use:

select SUM(WordCount) as 'words per day' 
from @WordsCount 
group by DateAdded

I don't see why you're also grouping by the word count....

Also, since the DateAdded likely is a DATETIME column including a time portion, you might want to group by just the date:

select SUM(WordCount) as 'words per day' 
from @WordsCount 
group by CAST(DateAdded AS DATE)

Update: if I try this, the query works just fine ....

DECLARE @WordsCnt TABLE (WordCount INT, DateAdded DATETIME)

INSERT INTO @wordsCnt(WordCount, DateAdded)
VALUES(96, '2008-11-07 09:16:31.810'),
      (32, '2008-11-07 15:26:27.547'),
      (25, '2008-11-23 16:05:39.640'),
      (62, '2008-12-03 12:33:03.110')

select CAST(DateAdded AS DATE), SUM(WordCount) as 'words per day' 
from @WordsCnt
group by CAST(DateAdded AS DATE)

and produces the output:

2008-11-07   128
2008-11-23    25
2008-12-03    62

I think this should give you word count per day

select      SUM(WordCount) as 'words per day' , cast(DateAdded as date) dateAdded
from        WordsCount 
group by    cast(DateAdded as date)