Exclude a field/property from the database with Entity Framework 4 & Code-First

问题

I will like to know that is there a way to exclude some fields from the database? For eg:

public class Employee
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string FatherName { get; set; }

    public bool IsMale { get; set; }
    public bool IsMarried { get; set; }

    public string AddressAs { get; set; }
}

How can I exclude the AddressAs field from the database?

回答1:

In the current version the only way to exclude a property is to explicitly map all the other columns:

builder.Entity<Employee>().MapSingleType(e => new {
  e.Id,
  e.Name,
  e.FatherName,
  e.IsMale,
  e.IsMarried
});

Because AddressAs is not referenced it isn't part of the Entity / Database.

The EF team is considering adding something like this:

builder.Entity<Employee>().Exclude(e => e.AddressAs);

I suggest you tell leave a comment on the EFDesign blog, requesting this feature :)

Hope this helps

Alex

回答2:

for future reference: you can use data annotations MSDN EF - Code First Data Annotations

[NotMapped]        
public string AddressAs { get; set; }

回答3:

I know this is an old question but in case anyone (like me) comes to it from search...

Now it is possible in entity framework 4.3 to do this. You would do it like so:

builder.Entity<Employee>().Ignore(e => e.AddressAs);

回答4:

It's also possible to add the column you want to ignore as a Shadow Property in the DbContext:

builder.Entity<Employee>().Property<string>("AddressAs");

Then you can query on that column like so:

context.Employees.Where(e => EF.Property<string>(e, "AddressAs") == someValue);

来源：https://stackoverflow.com/questions/1707663/exclude-a-field-property-from-the-database-with-entity-framework-4-code-first

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