小编S P*_*S P的帖子

我正在使用:

• Asp.net核心1.1
• MongoDB驱动程序2.4.4

我正在执行以下LINQ查询:

        var collection = _db.GetCollection<TableA>("TableAs");
        var collectionTableB = _db.GetCollection<TableB>("TableBs");
        var collectionTableC = _db.GetCollection<TableCs>("TableCs");


        var query = from c in collection.AsQueryable()
                    join i in (from f in collectionTableB.AsQueryable()
                               join p in collectionTableC.AsQueryable() 
                                    on f.PcbaId equals p.PcbaId into i
                               from x in i.DefaultIfEmpty()
                               select new { f, x })
                  on c.AssemblyId equals i.f.AssemblyId into cap
                    from i in cap.DefaultIfEmpty()
                    select new ConfigurableItemDto {

                    };

当我执行它时,它会抛出以下异常:

类型'System.Collections.Generic.IEnumerable`1 [TableB]'的表达式不能用于方法'System.Linq.IQueryable`1 [<> f__AnonymousType2'的类型'System.Linq.IQueryable`1 [TableB]'的参数`2 [TableB,System.Collections.Generic.IEnumerable`1 [TableC]]] GroupJoin [Assembly,Pcba,String,<> f__AnonymousType2`2](System.Linq.IQueryable`1 [TableB],System.Collections.Generic .IEnumerable`1 [TableC],System.Linq.Expressions.Expression`1 [System.Func`2 …