EF错误：“指定的LINQ表达式包含对与不同上下文关联的查询的引用。”

Question

我已经浏览了几个其他线程，这些线程引发了同样的错误，但没有得到解决方案：

        public IQueryable GetHolidays(IQueryable<Location> locations, Location currentLocation)
    {
        int currentLocationType = currentLocation.FkLocationTypeId;

        var holidays = ClientContext.Holidays;

        //get all holidays for the given locations
        var holidaysPerLocation = (
                                    //get permissions added in their own level
                                    from h in holidays
                                    where (from l in locations where l.FkLocationTypeId >= currentLocationType select l.LocationId).Contains(h.FkLocationId)
                                     && h.FkHolidayParentId == null
                                    select h)
                                    .Union
                                  ( 
                                    //get permissions overriden at the current level 
                                    from h in holidays
                                    where (from l in locations where l.FkLocationTypeId >= currentLocationType select l.LocationId).Contains(h.FkLocationId)
                                        && h.FkHolidayParentId != null && h.InheritedStatus == "U"
                                    select h).Union
                                  (
                                    //get holidays from parent levels which are opted in
                                    from h in holidays
                                    join h1 in holidays on h.HolidayId equals h1.FkHolidayParentId 
                                    where (from l in locations where l.FkLocationTypeId < currentLocationType select l.LocationId).Contains(h.FkLocationId)
                                        && h.InheritedStatus == "I"
                                    select h);

        return holidaysPerLocation;
    }

错误：“指定的LINQ表达式包含对与不同上下文关联的查询的引用。”

最初我试图直接在我的LINQ查询中查询ClientContext.Holidays，而不是单独将它带入内存，但这也给了我同样的错误。现在据我所知，我没有引用两个数据上下文，我不知道为什么会出现这个错误。