EF6 数据库优先 Table-外键的每类型多重性问题

Question

我对 EF 还很陌生，所以我希望这不是一个愚蠢的问题。我进行了搜索，但找不到与我的问题相关的任何内容。

我在 EF6 中对现有数据库建模时遇到问题。我的 TPT 继承设置如下：

TPT model 由于创建模型时出现问题，我必须手动添加 BAMS*Environment 表。一切都很好，直到我将外键从 BAMSPortalEnvironment 添加到 BAMSPrimeEnvironment。对于给定的 Prime 环境，可能有也可能没有 Portal 环境，但对于每个 Portal 环境，都有 Prime 环境。
我从 VS2017 收到以下错误：

Running transformation: Multiplicity is not valid in Role 'BAMSPortalEnvironment' in relationship 'FK_BAMSPortalEnvironment_BAMSPrimeEnvironment'. Because the Dependent Role properties are not the key properties, the upper bound of the multiplicity of the Dependent Role must be *.

相关表格的简化模型：

CREATE TABLE dbo.Environment(
  EnvironmentId     int IDENTITY(1,1) NOT NULL,
  EnvironmentTypeId char(1) NOT NULL,
  [Description]     varchar(64) NOT NULL,
  CONSTRAINT UQ_Environment UNIQUE NONCLUSTERED (EnvironmentId ASC) ON [PRIMARY],
  CONSTRAINT PK_Environment PRIMARY KEY CLUSTERED (EnvironmentId ASC, EnvironmentTypeId ASC) ON [PRIMARY]
) ON [PRIMARY];

CREATE TABLE dbo.BAMSPrimeEnvironment(
    EnvironmentId       int NOT NULL,
    EnvironmentTypeId   AS CAST('B' AS char(1)) PERSISTED NOT NULL,
    CONSTRAINT FK_BAMSPrimeEnvironment_Environment FOREIGN KEY (EnvironmentId, EnvironmentTypeId) REFERENCES dbo.Environment (EnvironmentId, EnvironmentTypeId) ON UPDATE NO ACTION ON DELETE CASCADE,
    CONSTRAINT PK_BAMSPrimeEnvironment PRIMARY KEY CLUSTERED (EnvironmentId ASC, EnvironmentTypeId ASC) ON [PRIMARY]
) ON [PRIMARY];

CREATE TABLE dbo.BAMSPortalEnvironment(
    EnvironmentId       int NOT NULL,
    EnvironmentTypeId   AS CAST('P' AS char(1)) PERSISTED NOT NULL,
    BAMSPrimeId         int NOT NULL,
    BAMSPrimeTypeId     AS CAST('B' AS char(1)) PERSISTED NOT NULL,
    CONSTRAINT FK_BAMSPortalEnvironment_BAMSPrimeEnvironment FOREIGN KEY (BAMSPrimeId, BAMSPrimeTypeId) REFERENCES dbo.BAMSPrimeEnvironment (EnvironmentId, EnvironmentTypeId) ON UPDATE NO ACTION ON DELETE NO ACTION,
    CONSTRAINT FK_BAMSPortalEnvironment_Environment FOREIGN KEY (EnvironmentId, EnvironmentTypeId) REFERENCES dbo.Environment (EnvironmentId, EnvironmentTypeId) ON UPDATE NO ACTION ON DELETE CASCADE,
    CONSTRAINT UQ_BAMSPortalEnvironment_BAMSPrimeId_BAMSPrimeTypeId UNIQUE NONCLUSTERED (BAMSPrimeId ASC, BAMSPrimeTypeId ASC) ON [PRIMARY],
    CONSTRAINT PK_BAMSPortalEnvironment PRIMARY KEY CLUSTERED (EnvironmentId ASC, EnvironmentTypeId ASC) ON [PRIMARY]
) ON [PRIMARY];

我可以通过将“0..1”更改为“*”来"fix"，但这并不能准确描述我的模型。我缺少什么才能使它正常工作？

这是我的第一个 post，所以如果您需要更多信息，请告诉我。

谢谢！

Answer 1

我找不到解决方案，所以我没有将 BAMSPortalEnvironment 引用 BAMSPrimeEnvironment，而是改为引用 Environment，这解决了这个问题。

EF6 数据库优先 Table-外键的每类型多重性问题

EF6 Database First Table-per-Type multiplicity issue on foreign key

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