EF6 Does not generate foreign key association from

问题:

PROBLEM:

I am trying to create a EF6 model using the database first approach. Simply speaking, I have 2 tables tblUser and tblMilkMan which have a foreign key relationship on the UserID column. But when I create a new EDMX diagram and add the 2 tables:

1. I dont see the relationship
2. No navigation properties are created

Please tell me what Im doing wrong!

DB Schema:

Table Scripts:

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 Designer View:

RELATED LINKS WHICH DIDNT HELP ME:

• Why doesn't EF 4 generate association for FK relation to column with unique index?

• EF does not generate foreign key association from foreign key in table

ENVIRONMENT:

• Visual Studio Ultimate 2012
• SQL Server 2014
• EF6
• Web API2

回答1:

The problem is the following line -

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

I do not know the reason behind having Clustered and NonClustered indexes on same column. A common best practice is to create a Primary Key as Clustered Index. (Source)

If you delete that NONCLUSTERED INDEX, it will see the relation in EDMX.

How to delete it?