c# – 在此上下文中仅支持基本类型(如Int32,String和Guid)

概述我收到以下错误： Unable to create a constant value of type ‘Phoenix.Intranet.Web.ClientSettings.ComponentRole’. Only primitive types (‘such as Int32, String, and Guid’) are supported in this context. 我明白为什么错误 我收到以下错误：

Unable to create a constant value of
type
‘Phoenix.Intranet.Web.ClIEntSettings.ComponentRole’.
Only primitive types (‘such as Int32,
String,and GuID’) are supported in
this context.

我明白为什么错误发生.我不明白的是为什么我的代码创建错误.我的比较是反对原始类型.所有比较都是GuID to GuID.该错误明确指出,圭IDs是好的.

该行发生错误(向下)：

var vla =  (from cir in phoenixEntitIEs.ComponentInRoles

码：

List<ComponentRole> roles;using (imsMembershipEntitIEs entitIEs = new imsMembershipEntitIEs()){    roles = (from role1 in entitIEs.Roles             select new ComponentRole{name = role1.Rolename,RoleID = role1.RoleID} ).ToList();}List<Components> componentInRoles;using (PhoenixEntitIEs phoenixEntitIEs = new PhoenixEntitIEs()){    phoenixEntitIEs.Contextoptions.LazyLoadingEnabled = false;    componentInRoles = (from component in phoenixEntitIEs.Components                        select new Components{name = component.name,ComponentID = component.ComponentID,//InRoles = (from componentInRole in phoenixEntitIEs.ComponentInRoles                                              //           join role in roles on componentInRole.RoleID equals role.RoleID                                               //           where componentInRole.ComponentID == component.ComponentID                                              //           select new ComponentRole{RoleID = role.RoleID,name = role.name})                                              }                       ).ToList();    foreach (Components cmpent in componentInRoles)    {        Components cmpent1 = cmpent;        //cmpent.InRoles =          var vla =  (from cir in phoenixEntitIEs.ComponentInRoles                     join role in roles on cir.RoleID equals role.RoleID                     where cir.ComponentID == cmpent1.ComponentID                         select role).ToList();    }}

解决方法 EntityFramework和linq to sql都尝试将这样的查询转换为sql IN *** 作符,这些查询是内存中的一部分,另一部分在数据库中.

并且因为你的类哪个角色是一个IEnumerable是不是一个原始类型,它不能被翻译成SQL查询.

您应该首先从数据库中获取内存,然后在内存中加入两个列表.

例如：

var vla =  (from cir in phoenixEntitIEs.ComponentInRoles.ToList()                     join role in roles on cir.RoleID equals role.RoleID                     where cir.ComponentID == cmpent1.ComponentID                         select role).ToList();

我希望我能帮忙

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