CODEWITHSUNDEEP
c#entity-framework
Travis J
Travis J

Reputation: 82297

Foreign key navigation property naming convention alternatives

When using Entity Framework 4.1, are there alternatives to the naming conventions for Navigation Properties?

For example instead of doing this:

public virtual MyObject MyObject { get; set; }

To be

public virtual MyObject SomeOtherName { get; set; }

UPDATE:

When the [ForeignKey("OldStepId")] and [ForeignKey("NewStepId")] attribute is added, the generated SQL then becomes:

{SELECT 
`Extent1`.`CompletedId`, 
`Extent1`.`OldStepId`, 
`Extent1`.`NewStepId`, 
`Extent1`.`Name`, 
`Extent1`.`Step_StepId`, 
`Extent1`.`Step_StepId1` 
FROM `Completed` AS `Extent1`}

which, the last two columns do not exist.

Upvotes: 2

Views: 1949

Answers (4)

Justin Pihony
Justin Pihony

Reputation: 67115

You can use the Data Annotations or the Fluent API to do this

Attribute Way

public virtual Int32 MyObjectId{get;set;}
[ForeignKey("MyObjectId")]
public virtual MyObject SomeOtherName { get; set; }

Fluent Way

modelBuilder.Entity<Type>()
    .HasRequired(p => p.SomeOtherName)
    .WithMany(d => d.Type)
    .HasForeignKey(p => p.MyObjectId)

RESPONSE TO UPDATE

If you have a List in your MyOjbect class, then you need to mark that List as [InverseProperty("SomeOtherName")]. This might be why you are getting extra columns in your SQL. This keeps two-way relationships from being doubled up by telling the generator where the main column really is.

Upvotes: 4

Slauma
Slauma

Reputation: 177163

You can name them as you like. You must distinguish between navigation properties which have a (scalar) foreign key property exposed in the class ("Foreign Key associations") and navigation properties which have not ("Independent Associations"):

Foreign Key associations:

[ForeignKey("VeryDifferentFKPropertyName")]     // refers to property, NOT column
public virtual MyObject SomeOtherName { get; set; }

[Column("JustAnotherColumnName")]               // map property to column name
public int VeryDifferentFKPropertyName { get; set; }

With Fluent API:

modelBuilder.Entity<SomeEntity>()
    .HasRequired(e => e.SomeOtherName)   // or .HasOptional(...)
    .WithMany()
    .HasForeignKey(e => e.VeryDifferentFKPropertyName);

modelBuilder.Entity<SomeEntity>()
    .Property(e => e.VeryDifferentFKPropertyName)
    .HasColumnName("JustAnotherColumnName");

Independent Associations:

public virtual MyObject SomeOtherName { get; set; }

You can map the foreign key column name only with Fluent API:

modelBuilder.Entity<SomeEntity>()
    .HasRequired(e => e.SomeOtherName)   // or .HasOptional(...)
    .WithMany()
    .Map(a => a.MapKey("JustAnotherColumnName"));

Upvotes: 0

Brian Mains
Brian Mains

Reputation: 50728

If you add a T4 template to generate the content, you can pretty much adjust the naming scheme to whatever you want...

Upvotes: 0

LenPopLilly
LenPopLilly

Reputation: 1227

I generally call them the same name as the Foreign Key for the Nav Props.

Upvotes: 1

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