Getting two counts and then dividing them

Question

I am attempting to get two counts and then divide those two counts to get the ratio of the items I am counting. I saw this post here and tried that. I am getting an error in my

Answer 1

The structure of your query bothers me. You can do it much more efficiently as:

SELECT A.NUMer, A.DENOM, cast(A.NUMer as float)/A.DENOM 
FROM (SELECT COUNT(case when drg_no IN (061,062,063,064,065,066) then DRG_NO
                   end ) as Numer,
             count(case when drg_no IN 061,062,063,064,065,066,067,068,069) then DRG_NO
                   end) as denom
      FROM smsdss.BMH_PLM_PtAcct_V
      WHERE drg_no IN (061,062,063,064,065,066)
        AND Adm_Date BETWEEN @SD AND @ED
        AND PLM_PT_ACCT_TYPE = 'I'
     ) a

This doesn't affect the integer divide issue, but your original query is overcomplicated.