Oracle achieves year-over-year data and growth percentage

Select c.*,round ((datanow-databefore)/databefore,2) *100| | ' % ' Datapercent from (select A.auth_tztype, A.datanow,b.databefore from
(select Auth_tztype,count (auth_tztype) Datanow from T_author where auth_applydate between To_date (' 2011/1/1 ', ' yyyy/mm/ DD Hh24:mi:ss ') and to_date (' 2011/12/31 ', ' yyyy/mm/dd hh24:mi:ss ') group by Auth_tztype) a
Left JOIN (select Auth_tztype,count (auth_tztype) Databefore from T_author where auth_applydate between To_date (' 2010/1/1 ', ' yyyy/mm/dd hh24:mi:ss ') and to_date (' 2010/12/31 ', ' yyyy/mm/dd hh24:mi:ss ') group by Auth_tztype) b on a.auth_tztype=b. Auth_tztype) C

Red for percent function

Oracle achieves year-over-year data and growth percentage for the current period