报错信息：

 08-17 23:48:10.223: E/SQLiteLog(11984): (1) no such column: MessageHistory.MessageTime
08-17 23:48:10.233: E/ContactsDatabase(11984): getMessages debug, error : no such column: MessageHistory.MessageTime (code 1): , while compiling: select * from (select * from MessageHistory inner join _User on MessageHistory.[ReceUserId] = _User.[objectId] order by  MessageHistory.[MessageTime] ) group by ReceUserId;

可以确定的是代码中所有涉及到的列在数据库里都是存在的。
查询代码：

 SQLiteDatabase db = getReadableDatabase();
            Cursor c = db.rawQuery("select * from (select * from MessageHistory inner join _User on MessageHistory.[ReceUserId] = _User.[objectId] order by  MessageHistory.[MessageTime] ) group by ReceUserId;", null);
            c.moveToFirst();
            while (c.moveToNext()) {
            }

所以问题到底出在哪里？求大神帮忙解答！