prepareStatement中的in查詢

 近日項目中,用prepareStatement操作數據庫,涉及到sql的in查詢，在PLSQL中測試,有數據,但放在項目中就查不出數據

 

String reportsql=" select to_char(action_date,'yyyy-mm') action_date, tt.ad_name ad_name, t.ad_site ad_site, t.m_browse_num click_num,"
  + " t.m_login_user_num login_user_num, t.m_integrality_cv_num m_integrality_cv_num from m_user_from_ad_stat t, b_ad tt where t.action_date = to_date(?,'yyyymm')"
  + " and t.ad_id = tt.ad_id and t.ad_id in ? order by 1, 2, 3 ";

 

後查資料得知,prepareStatement.set(2,n).其中不論n是數組還是任何變量,都作爲一個單體傳入操作,比如n爲{1,2,3},傳入後sql回去查 是否有t.ad_id in "{1,2,3}"而不是查 t.ad_id  in (1,2,3)

 

解決方案: 

//拼接in後面的條件，形成多個"?",長度跟數組長度相同

String[] adids={"1","2","3"};

String inString="";
 for(int i=0;i<adids.length;i++){
     if(i>0){
       inString+=",";
     }
     inString+="?";
 }

 con=getDSconn();
       stmt = con.prepareStatement(reportsql);
       stmt.setString(1,startdate);
       for(int j=0;j<adids.length;j++){
       stmt.setString(j+2,adids[j]);
       }
       rs = stmt.executeQuery();
      
   while(rs.next())
 {......}

 

參考文獻 :http://www.javaeye.com/topic/209740