实体框架自定义字段持久性

Question

I am using the Entity Framework with a database first approach.

I have used partial classes to successfully add custom methods, but have found that if I add a custom field it is not persisted when my entity is next pulled from the DataContext (entity is not submitted to database in the meantime). I need to use this field for processing but I do not need it, or want it, stored in my database.

public partial class MyEntity
{           
    public decimal MyCustomField;
}

Why is this? How can I get around it?

Thanks

Answer 1

One thing you should keep in mind is that Entity Framework do not store values in itself, it just generates SQL queries using its knowledge of database from EDMX. Persistence is actually implemented at the database side.

Yes, you can add custom methods and properties to model using partial classes, but since, you are not creating a database column, the values in those properties will not be persisted and hence the behavior you are getting is perfectly normal.

I hope this helps.

Answer 2

尝试使用“属性”而不是“字段”。

public decimal MyCustomField{get; set;}