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

Question

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?

Possible duplicate of [Ignoring a class property in Entity Framework 4.1 Code First](http://stackoverflow.com/questions/10385248/ignoring-a-class-property-in-entity-framework-4-1-code-first) — Michael Freidgeim, Aug 26 '16 at 05:14

score 80 · Answer 1 · edited Mar 14 '16 at 15:34

80

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

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

edited Mar 14 '16 at 15:34

Martin

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answered Dec 26 '13 at 14:03

markwilde

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score 35 · Answer 2 · answered Mar 09 '12 at 12:26

35

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);

answered Mar 09 '12 at 12:26

kmp

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Or in VB `builder.Entity(Of Employee).Ignore(Function(e) e.AddressAs)` – Michal B. May 23 '12 at 08:54
4

Would this be global? I mean, what if I want to do it for just this one call? Can I turn it back on, so to speak? – vbullinger Apr 08 '13 at 14:10
Yes still useful. you just saved me 40 minutes of research. – demo.b Aug 30 '15 at 14:31

score 22 · Accepted Answer · answered Nov 30 '09 at 02:53

22

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

answered Nov 30 '09 at 02:53

Alex James

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I realized that the only way to do it as of today is the way you mentioned. I posted it on EFDesign blog a long back: http://blogs.msdn.com/efdesign/archive/2009/10/12/code-only-further-enhancements.aspx – Yogesh Nov 30 '09 at 04:25
Would be a real bonus if they add a `.Exclude()` – Zapnologica Jun 11 '15 at 20:32
Is there a way to exclude a particular field from all classes in a model using the T4 template? – Bat_Programmer Aug 29 '16 at 02:03

score 0 · Answer 4 · answered Jul 09 '18 at 19:53

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);

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

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