'指定的LINQ表达式包含对与不同上下文关联的查询的引用'的含义

Question

我有以下Action方法: -

public ActionResult Index(string searchTerm=null, int page = 1)
        {
            var racks = repository.AllFindRacks(searchTerm).OrderBy(a=>a.Technology.Tag).ToPagedList(page, 5) ;

            if (Request.IsAjaxRequest())
            {

                return PartialView("_RackTable", racks);
            }
            return View(racks);
        }

以下Repository方法: -

public IQueryable<RackJoin> AllFindRacks(string q)
        {
            List<RackJoin> rakjoin = new List<RackJoin>();
            var result = from rack in tms.TMSRacks
           .Include(rack => rack.DataCenter)
           .Include(rack => rack.Zone)
           .Include(rack => rack.TMSFirewalls)
           .Include(rack => rack.TMsRouters)
           .Include(rack => rack.TMSServers)
           .Include(rack => rack.TMSStorageDevices)
           .Include(rack => rack.TMSSwitches)
           .Include(rack => rack.Technology)
                         join resource in entities.Resources
                         .Include(a => a.ComponentDefinition)
                           .Include(a => a.ResourceLocation.SiteDefinition.SDOrganization)
                           .Include(a => a.ResourceLocation.SiteDefinition.AccountDefinition.SDOrganization)
                         on rack.Technology.IT360ID equals resource.RESOURCEID
                         where (q == null || rack.Technology.Tag.ToUpper().StartsWith(q.ToUpper()))
                         select new RackJoin { 
                         Rack = rack,
                         Resource = resource,
                         Customer = resource.ResourceLocation.SiteDefinition.AccountDefinition.SDOrganization,
                         Site = resource.ResourceLocation.SiteDefinition.AccountDefinition.SDOrganization,
                         Technology = rack.Technology

                         };
            return result;

        }

但是当我调用Action方法时,我得到以下异常: -

用户代码未处理System.NotSupportedException
HResult = -2146233067 Message =指定的LINQ表达式包含对与不同上下文关联的查询的引用.
Source = System.Data.Entity StackTrace:

Answer 1

看起来您正在加入来自两个不同上下文的数据:tms和实体.

这在LINQ中是不可能的,因为它们都有自己的数据库连接和完全独立的模型.

EF无法将其转换为SQL语句.(据他所知,这些表可能存在于不同的数据库中)

您需要将所有实体移动到单个上下文或单独执行两个查询,然后将它们连接到内存中.(如果所有表都在同一个数据库中,请使用第一个选项,如果您有单独的数据库,请使用第二个选项)