Question

以下查询在EF5上运行良好，但在EF6上给出了错误。我使用DbContext和CodeFirst。

使用EF6引发错误：

无法转换类型'System.Linq.IQueryable 1[[<>f__AnonymousType5 4 [[System.Int32，mscorlib，Version = 4.0.0.0，Culture = neutral，PublicKeyToken = b77a5c561934e089]，[System.Int32，mscorlib， Version = 4.0.0.0，Culture = neutral，PublicKeyToken = b77a5c561934e089]，[System.Int32，mscorlib，Version = 4.0.0.0，Culture = neutral，PublicKeyToken = b77a5c561934e089]，[System.Int32，mscorlib，Version = 4.0.0.0， Culture = neutral，PublicKeyToken = b77a5c561934e089]]，Wms.Domain，Version = 1.0.0.0，Culture = neutral，PublicKeyToken = 85d69d39f5becc93]]'输入'System.Data.Entity.Core.Objects.ObjectQuery 1[[<>f__AnonymousType5 4 [[System.Int32，mscorlib，Version = 4.0.0.0，Culture = neutral，PublicKeyToken = b77a5c561934e089]，[System.Int32，mscorlib，Version = 4.0.0.0，Culture = neutral，PublicKeyToken = b77a5c561934e089]，[System.Int32， mscorlib，Version = 4.0.0.0，Culture = neutral，PublicKeyToken = b77a5c561934e089]，[System.Int32，mscorlib，Version = 4.0.0.0，Culture = neutral，PublicKeyToken = b77a5c561934e089]]，Wms.Domain，Version = 1.0.0.0， Culture = neutral，PublicKeyToken = 85 d69d39f5becc93]]”。 LINQ to Entities仅支持转换EDM原语或枚举类型。

查询（简化）：

var unitsPerPosition = context.Positions.Include(p => p.Unit).Select(x => new { Unit = x.Unit, Position = x });

var orders = (
                from order in context.Orders.Include(x => x.SourceLocation);
                join unitPosition in unitsPerPosition on order.UnitId equals unitPosition.Unit.UnitId
                group new { order, unitPosition } by new { LocationId = order.SourceLocationId, Level = unitPosition.Position.Level } into groupOrders
                where groupOrders.Key.LocationId != null
                select new { 
                    LocationId = groupOrders.Key.LocationId.Value, 
                    Level = groupOrders.Key.Level, 
                    LoadingOrders = groupOrders.Count(), 
                    UnloadingOrders = -1 }
            );

IList<LocationChannels> searchResult = (from s in context.Locations
        .Include(s => s.Positions)
        .Include(s => s.Positions.Select(sp => sp.Unit))

        let channels = from p in s.Positions
                        where p.LocationId == s.LocationId
                        group p by new { p.LocationId, p.Column, p.Level } into channelsGroup

                        join order in orders on new { channelsGroup.Key.LocationId, channelsGroup.Key.Level } 
                        equals new { order.LocationId, order.Level } into ordersGroup
                        from o in ordersGroup.DefaultIfEmpty()

                        select new Channel
                        {
                            LocationId = channelsGroup.Key.LocationId,
                            Column = channelsGroup.Key.Column,
                            Level = channelsGroup.Key.Level
                        }

        select new LocationChannels
                      {
                        Location = s,
                        Channels = channels,
                      })
    .Where(predicate).ToList();

问题似乎出现在左边连接中，并在变量'orders'中加载了匿名类型。我还尝试在'orders'查询中添加ToList（），然后将错误更改为：

无法创建“匿名类型”类型的常量值。在此上下文中仅支持原始类型或枚举类型。

有人能给我一个如何解决它的提示吗？

更新：该错误已在EF 6.0.2中得到确认和解决。 See the Issue on CodePlex.

Answer 1

正如dna2在他的问题末尾所指出的那样，这个问题已在EF 6.0.2中修复。要升级您的EF版本，请在程序包管理器控制台（VS2013 VIEW -> Other Windows -> Package Manager Console）中执行以下操作。

Update-Package EntityFramework -Version 6.0.2

无法将“System.Linq.IQueryable”中的匿名类型转换为“System.Data.Entity.Core.Objects.ObjectQuery”

1 个答案: