实体框架多对多关系避免导致错误

我看过各种SO问题，但找不到一个类似于我的情况。我有下面的EF模型生成的类

public partial class Resource
{
    public Resource()
    {
         this.Roles = new HashSet<Role>();
    }
    public int Id { get; set; }
    public string Name { get; set; }
    public virtual ICollection<Role> Roles { get; set; }
}
public partial class Role
{
    public Role()
    {
        this.Resources = new HashSet<Resource>();
        this.Users = new HashSet<User>();
    }
    public int Id { get; set; }
    public string Name { get; set; }
    public string Description { get; set; }
    public Nullable<bool> Active { get; set; }
    public virtual ICollection<Resource> Resources { get; set; }
    public virtual ICollection<User> Users { get; set; }
}
public aysnc Task<int> SaveRelationship(params)
{
     var db = GetContext();
     var role = await db.Roles.FirstOrDefaultAsync(...);
     var resource = await db.Resources.FirstOrDefaultAsync(...);
     role.Resources.Add(resource);
     //tried these one at a time as well as together
     resource.Roles.Add(role);
     return await db.SaveChangesAsync();
}

我得到错误INSERT语句与FOREIGN KEY约束冲突..

它生成/执行的SQL查询是:我知道这个语句不会运行，我能做些什么来改变它生成正确的语句?

exec sp_executesql N'INSERT [Config].[RoleResourceAllocations]([RoleId])
VALUES (@0)
SELECT [ResourceId]
FROM [Config].[RoleResourceAllocations]
WHERE @@ROWCOUNT > 0 AND [ResourceId] = scope_identity() AND [RoleId] = @0',N'@0 int',@0=1

这是我的表

CREATE TABLE [Config].[RoleResourceAllocations]
(
    [ResourceId] [int] IDENTITY(1,1) NOT NULL,
    [RoleId] [int] not null, 
    CONSTRAINT [FK_RoleResourceAllocations_Roles] 
        FOREIGN KEY ([RoleId]) REFERENCES [Identity].[Roles]([Id]),
    CONSTRAINT [FK_RoleResourceAllocations_Resources] 
        FOREIGN KEY ([ResourceId]) REFERENCES [Config].[Resources]([Id]), 
    CONSTRAINT [PK_RoleResourceAllocations] 
        PRIMARY KEY ([RoleId], [ResourceId])
)