code首先CTP4：表没有主键？ [英] Code First CTP4: Table with no primary key?

问题描述

通过实体框架和code首先，有没有可能让它创建和使用表没有主键？我不能让这样的设置工作：

With Entity Framework and Code First, is it possible to let it create and use a table with no primary keys? I can't get this setup to work:

public class Report
{
    public virtual int ReportId
    public virtual ICollection<ReportChanges> ReportChanges
}

public class ReportChanges
{
    public virtual Report Report
    public virtual string EditorName
    public virtual DateTime Changed
}

请注意，我已经被排除在分配一个ReportChanges主键。但是，在此设置，我得到：的无法推断出密钥的实体类型ReportChanges 的

Note that I've excluded assigning a primary key in ReportChanges. But with this setup I get: "Unable to infer a key for entity type 'ReportChanges'".

无论我失去了一些东西，或code首先不支持没有主键的表。什么是正确的？ 谢谢你。

Either I'm missing something, or Code First doesn't support tables with no primary keys. What is correct? Thanks.

推荐答案

在EF可以支持一个表，没有PI如果还有一种方法来唯一地标识某一行，的但的它不能推断的唯一标识没有正确的PK。换句话说，骗了EF，说有一个PK，比如，在报告和更改。

The EF can support a table with no PI if there is still a way to uniquely identify a row, but it can't infer the unique identifier without a proper PK. In other words, lie to the EF and say that there is a PK, say, on Report and Changed.

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