实体框架代码优先:如何忽略类 [英] Entity Framework code first: How to ignore classes

问题描述

这类似于问题此处和此处，但这些文件已过时并且没有任何用处答案.

This is similar to questions here and here, but those are old and have no good answers.

假设我有以下课程:

class HairCutStyle { 
   public int ID { get; set; }
   public string Name { get; set; }
}

class CustomerHairCutPreference {
   public int ID { get; set; }
   public Customer Customer { get; set; }
   public HairCutStyle HairCutStyle { get; set; }
}

比方说，我的HairCutStyle数据存储在另一个数据库的表中(我从Paul Mitchell自己得到).我想将HairCutStyle类用作POCO类-我将在代码中使用该类来表示理发样式，但无需在数据库中读取/写入该信息. (假设我有一个单独的服务层，可以从另一个数据库填充这些类的数据.)

Let's say my HairCutStyle data is stored in a table in another database (I get it from Paul Mitchell himself). I want to use the HairCutStyle class as a POCO class - something that I will use in code to represent hair cut styles, but I don't need to read/write that information in my database. (Assume I have a separate service layer that can populate the data for these classes from the other database.)

如何告诉EF不要在当前数据库上下文中创建HairCutStyle表?但同时，我想在CustomerHairCutPreference表中存储一个值，该值是对存储在其他位置的HairCutStyle数据的引用.某种虚拟"外键，不受实际数据库FK约束的约束.

How can I tell EF NOT to create a HairCutStyle table in my current db context? But at the same time, I want to store a value in the CustomerHairCutPreference table that is a reference to the HairCutStyle data stored elsewhere. A "virtual" foreign key of sorts, that isn't constrained by an actual database FK constraint.

推荐答案

要确保三件事:

1. 确保您没有在DbContext派生类中公开DbSet<HairCutStyle>
2. 确保您在OnModelCreating替代项中没有提及HairCutStyle
3. 使用NotMapped属性标记您的HairCutStyle属性.

1. Make sure you do not expose a DbSet<HairCutStyle> in your DbContext-derived class
2. Make sure you do not have any mention of HairCutStyle in your OnModelCreating override
3. Mark your HairCutStyle property using the NotMapped attribute.

这篇关于实体框架代码优先:如何忽略类的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！