EF6 不从数据库生成外键关联

PROBLEM:

我正在尝试使用数据库优先方法创建 EF6 模型。简单来说，我有2张桌子tblUser and tblMilkMan上有外键关系UserID柱子。但是当我创建一个新的 EDMX 图并添加 2 个表时：

1. 我看不到其中的关系
2. 未创建导航属性

请告诉我我做错了什么！

数据库架构：

表脚本：

CREATE TABLE [dbo].[tblMilkMan]
    (
      [RecordID] [INT] NOT NULL
                       IDENTITY(1, 1) ,
      [UserID] [INT] NOT NULL ,
      [IsMyTurn] [BIT] NOT NULL ,
      [RoundRobinOrder] [INT] NOT NULL
    )
ON  [PRIMARY]
GO
ALTER TABLE [dbo].[tblMilkMan] ADD CONSTRAINT [PK_tblMilkMan] PRIMARY KEY CLUSTERED  ([RecordID]) ON [PRIMARY]
GO
ALTER TABLE [dbo].[tblMilkMan] ADD CONSTRAINT [FK__MilkMan__User__UserID] FOREIGN KEY ([UserID]) REFERENCES [dbo].[tblUser] ([UserID]) ON DELETE CASCADE
GO

CREATE TABLE [dbo].[tblUser]
    (
      [UserID] [INT] NOT NULL
                     IDENTITY(1, 1) ,
      [LogonName] [VARCHAR](20) COLLATE SQL_Latin1_General_CP437_CI_AS
                                NOT NULL ,
      [Client] [CHAR](4) COLLATE SQL_Latin1_General_CP437_CI_AS
                         NOT NULL ,
      [Password] [VARCHAR](20) COLLATE SQL_Latin1_General_CP437_CI_AS
                               NOT NULL ,
      [PasswordExpires] [DATETIME] NULL ,
      [PasswordExpiresAfter] [INT] NOT NULL
                                   CONSTRAINT [DF_tblUser_PasswordExpiresAfter] DEFAULT ( 9999 ) ,
      [FirstName] [VARCHAR](20) COLLATE SQL_Latin1_General_CP437_CI_AS
                                NOT NULL ,
      [LastName] [VARCHAR](20) COLLATE SQL_Latin1_General_CP437_CI_AS
                               NOT NULL
    )
ON  [PRIMARY]
    WITH (
         DATA_COMPRESSION = ROW)

GO
ALTER TABLE [dbo].[tblUser] ADD CONSTRAINT [PK_tblUser] PRIMARY KEY CLUSTERED  ([UserID]) WITH (DATA_COMPRESSION = ROW) ON [PRIMARY]
GO
CREATE UNIQUE NONCLUSTERED INDEX [IX_tblUser] ON [dbo].[tblUser] ([UserID]) WITH (FILLFACTOR=90, DATA_COMPRESSION = ROW) ON [PRIMARY]
GO

EDMX 设计器视图：

对我没有帮助的相关链接：

• 为什么 EF 4 不生成与列的 FK 关系的关联 唯一索引？ https://stackoverflow.com/questions/3511095/why-doesnt-ef-4-generate-association-for-fk-relation-to-column-with-unique-inde

• EF 不会生成外键关联 表中的外键 https://stackoverflow.com/questions/4140426/ef-does-not-generate-foreign-key-association-from-foreign-key-in-table

环境：

• Visual Studio 旗舰版 2012
• SQL Server 2014
• EF6
• Web API2

问题是下面一行 -

CREATE UNIQUE NONCLUSTERED INDEX [IX_tblUser] ON [dbo].[tblUser] ([UserID])
WITH (FILLFACTOR=90, DATA_COMPRESSION = ROW) ON [PRIMARY]
GO

我不知道同一列上有聚集索引和非聚集索引的原因。常见的最佳实践是将主键创建为聚集索引。(Source) http://blog.sqlauthority.com/2013/02/10/sql-server-primary-key-and-nonclustered-index-in-simple-words/

如果你删除那个非聚集索引，它将在 EDMX 中看到关系。

怎么删除呢？