Question

如何在使用union all查询时在desc中排序日期。现在让我解释我的问题我已经使用union all查询从两个表中获取数据现在我需要在desc中订购数据，当我尝试执行时获取日期格式：第一个ORDER BY术语与任何列都不匹配结果集

让我发布我迄今为止尝试过的代码：

 public List<VisitModel> visitLists(int id,String date){
 String visitquery= " Select * from ( Select  "  + VisitModel.Visit_TravelorCallFlag  + " ," + VisitModel.Visit_ID  + " AS " + VisitModel.Visit_ActionTaken  + " ," + VisitModel.Visit_CheckInDate  + " AS " + VisitModel.Visit_Createdat  +  " ," +  VisitModel.Visit_CheckOutDate  +  " AS " + VisitModel.Visit_LastModifiedat + " ," + VisitModel.Visit_EmployeeName  +  " AS " + VisitModel.Lat + " ," + VisitModel.Visit_Createdby   +  " AS " + VisitModel.Long +  "  FROM " + VisitModel.Visit_Table + " WHERE " + VisitModel.Visit_IncidentID + " =" + id  + " and strftime('%Y-%m-%d', " + VisitModel.Visit_CheckInDate  +") = '" + date  +"' "   +   " UNION ALL "  + " SELECT "  + VisitModel.Visit_TravelorCallFlag + " ," + VisitModel.Visit_TravelID  + " AS " + VisitModel.Visit_ActionTaken +  " ," + VisitModel.Visit_CheckInDate + " AS" + VisitModel.Visit_Createdat + " ," + VisitModel.Visit_CheckOutDate + " AS " + VisitModel.Visit_LastModifiedat + " ," + VisitModel.Visit_StartLat  +  " AS " +  VisitModel.Lat +  " ," + VisitModel.Visit_EndLat +  " AS " +VisitModel.Long  +" FROM " + VisitModel.Visit_TravelTable + " WHERE " + VisitModel.Visit_TravelIncidentID + " =" + id + " and strftime('%Y-%m-%d', " + VisitModel.Visit_CheckInDate  +") = '" + date  +"' )" + " order by  date (" + VisitModel.Visit_Createdat  + " ) DESC " ;


        Cursor cursor = db.rawQuery(visitquery ,null);
        List<VisitModel>lisobj=new ArrayList<>();
        if (cursor != null && cursor.getCount() > 0) {
            if (cursor.moveToFirst()) {
                do {
                    VisitModel visitobjs= new VisitModel();
                    visitobjs.setStartLat(cursor.getString(cursor.getColumnIndex(VisitModel.Lat)));
                    visitobjs.setStartLong(cursor.getString(cursor.getColumnIndex(VisitModel.Long)));
                    /*       String kil=cursor.getString(cursor.getColumnIndex(VisitModel.Visit_Kilometer));
                    visitobjs.setKilometer(kil);
                    String time=cursor.getString(cursor.getColumnIndex(VisitModel.Visit_CheckInDate));
                    visitobjs.setCheckInDate(time);
                    String nextdate=cursor.getString(cursor.getColumnIndex(VisitModel.Visit_CustOffDate));
                    String endlat=cursor.getString(cursor.getColumnIndex(VisitModel.Visit_CallSlipNo ));
                    visitobjs.setEndLat(endlat);
                    visitobjs.setNextVisitDate(nextdate);
                    String startlat=cursor.getString(cursor.getColumnIndex(VisitModel.Visit_Distance));
                    visitobjs.setStartLat(startlat);
                    String empname=cursor.getString(cursor.getColumnIndex(VisitModel.Visit_EndLong));
                    visitobjs.setEmployeeName(empname);*/
                    String checkin=cursor.getString(cursor.getColumnIndex(VisitModel.Visit_Createdat));
                    String checkout=cursor.getString(cursor.getColumnIndex(VisitModel.Visit_LastModifiedat));
                    visitobjs.setCheckInDate(checkin);
                    visitobjs.setCheckOutDate(checkout);
                    int flag=cursor.getInt(cursor.getColumnIndex(VisitModel.Visit_TravelorCallFlag));
                    int primarykey=cursor.getInt(cursor.getColumnIndex(VisitModel.Visit_ActionTaken));
                    visitobjs.setID(primarykey);
                    visitobjs.setTravelrVisitFlag(flag);
                    lisobj.add(visitobjs);
                }
                while (cursor.moveToNext());
            }
        }
        cursor.setNotificationUri(mcontext.getContentResolver(), VisitDAO_URI);
        return lisobj;
    }

得到：`第一个ORDER BY术语与结果集中的任何列都不匹配

任何人都能告诉我解决方案是什么意思！

Answer 1

而不是

" order by  date (" + VisitModel.Visit_CheckInDate  + " ) DESC "

尝试

" order by  date (" + VisitModel.Visit_Createdat  + " ) DESC "

当您使用UNION组合多个查询时，将对整个结果集进行排序，因此您必须使用结果集中的相同列。在这种情况下，这意味着您必须提供列的别名。

编辑试试这个：

String visitquery= 
"SELECT * FROM (
 Select  "  + VisitModel.Visit_TravelorCallFlag  + " ," + VisitModel.Visit_ID  + " AS " + VisitModel.Visit_ActionTaken  + " ," + VisitModel.Visit_CheckInDate  + " AS " + VisitModel.Visit_Createdat  +  " ," +  VisitModel.Visit_CheckOutDate  +  " AS " + VisitModel.Visit_LastModifiedat + " ," + VisitModel.Visit_EmployeeName  +  " AS " + VisitModel.Lat + " ," + VisitModel.Visit_Createdby   +  " AS " + VisitModel.Long +  "  FROM " + VisitModel.Visit_Table + " WHERE " + VisitModel.Visit_IncidentID + " =" + id  + " and strftime('%Y-%m-%d', " + VisitModel.Visit_CheckInDate  +") = '" + date  +"' "   +   
" UNION ALL "  + 
" SELECT "  + VisitModel.Visit_TravelorCallFlag + " ," + VisitModel.Visit_TravelID  + " AS " + VisitModel.Visit_ActionTaken +  " ," + VisitModel.Visit_CheckInDate + " AS" + VisitModel.Visit_Createdat + " ," + VisitModel.Visit_CheckOutDate + " AS " + VisitModel.Visit_LastModifiedat + " ," + VisitModel.Visit_StartLat  +  " AS " +  VisitModel.Lat +  " ," + VisitModel.Visit_EndLat +  " AS " +VisitModel.Long  +" FROM " + VisitModel.Visit_TravelTable + " WHERE " + VisitModel.Visit_TravelIncidentID + " =" + id + " and strftime('%Y-%m-%d', " + VisitModel.Visit_CheckInDate  +") = '" + date  +"' " + " 

)order by  3 DESC " ;

Answer 2

请使用以下示例，在使用union

合并两个查询后按列号完成排序

SELECT * FROM ( 
   SELECT * FROM  TABLE_1
   UNION 
   SELECT * FROM  TABLE_2 )
 ORDER BY 2 DESC

在sqlite android中使用Union查询时如何在desc中按顺序排序？

2 个答案: