sql - How to pass the data to OracleCommand Class c# -

i trying pass variable sql script , run in using c#.

i error saying

"missing expression".

fromdate , todate passed 'dd//mm//yy format. not passing parametres coorectly using oraclecommand ?

public void transactionreport(string fromdate, string todate)         {             string query = "select s.store_code,count(i.invc_sid) count invoice_v left join store_v s on i.sbs_no = s.sbs_no , i.store_no = s.store_no where(i.created_date between to_date(@fromdate,'mm//dd//yy') , to_date(@todate,'mm//dd//yy'))  , i.proc_status not in ('131072','65536','147456', '81920') , i.invc_type = 0 , i.sbs_no = 6  group  s.store_code";             conn.open();             using (oraclecommand cmd = new oraclecommand(query, conn))             {                 cmd.parameters.add(new oracleparameter("fromdate", fromdate));                 cmd.parameters.add(new oracleparameter("todate", todate));                 oracledatareader dr = cmd.executereader(); 

try : instead of @

string query = "select s.store_code,count(i.invc_sid) count invoice_v left join store_v s on i.sbs_no = s.sbs_no , i.store_no = s.store_no where(i.created_date between to_date(:fromdate,'mm//dd//yy') , to_date(:todate,'mm//dd//yy'))  , i.proc_status not in ('131072','65536','147456', '81920') , i.invc_type = 0 , i.sbs_no = 6  group  s.store_code";