EF 4.1 RC Code First - Mapping to existing database & specifying foreign key name
I have two classes. A Company has a County set against it:
public class Company
{
public int Id { get; set; }
public string CompanyName { get; set; }
public Country HomeCountry { get; set; }
}
public class Country
{
public int Id { get; set; }
public开发者_Go百科 string Code { get; set; }
public string Name { get; set; }
}
I am trying to map to an existing database where the Company table contains the foreign key of the Country record. So I presumably need to tell code first the name of the foreign key column.
Below is the complete code example. It's currently failing with different exceptions based on different things that I try. There's seems to be a lack of cohesive documentation on this as yet.
So using Code First Fluent API how do I define the name of the foreign key column?
Test app:
Create database as follows: CREATE DATABASE CodeFirst; GO
Use CodeFirst
create table Companies
(
Id int identity(1,1) not null,
HomeCountryId int not null,
Name varchar(20) not null,
constraint PK_Companies primary key clustered (Id)
)
create table Countries
(
Id int identity(1,1) not null
, Code varchar(4) not null
, Name varchar(20) not null
, constraint PK_Countries primary key clustered (Id)
)
alter table Companies
add
constraint FK_Company_HomeCountry foreign key (HomeCountryId)
references Countries (Id) on delete no action
Now run the following C# app:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.Entity.ModelConfiguration;
using System.ComponentModel.DataAnnotations;
using System.Data.Entity;
using System.Data;
namespace CodeFirstExistingDatabase
{
class Program
{
private const string ConnectionString = @"Server=.\sql2005;Database=CodeFirst;integrated security=SSPI;";
static void Main(string[] args)
{
// Firstly, add a country record, this works fine.
Country country = new Country();
country.Code = "UK";
country.Name = "United Kingdom";
MyContext myContext = new MyContext(ConnectionString);
myContext.Countries.Add(country);
myContext.Entry(country).State = EntityState.Added;
myContext.SaveChanges();
Console.WriteLine("Saved Country");
// Now insert a Company record
Company company = new Company();
company.CompanyName = "AccessUK";
company.HomeCountry = myContext.Countries.First(e => e.Code == "UK");
myContext.Companies.Add(company);
myContext.Entry(company).State = EntityState.Added;
myContext.Entry(country).State = EntityState.Unchanged;
myContext.SaveChanges();
Console.WriteLine("Saved Company"); // If I can get here I'd he happy!
}
}
public class MyContext
: DbContext
{
public DbSet<Company> Companies { get; set; }
public DbSet<Country> Countries { get; set; }
public MyContext(string connectionString)
: base(connectionString)
{
Database.SetInitializer<MyContext>(null);
Configuration.LazyLoadingEnabled = false;
Configuration.ProxyCreationEnabled = false;
}
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Configurations.Add(new CountryConfiguration());
modelBuilder.Configurations.Add(new CompanyConfiguration());
base.OnModelCreating(modelBuilder);
}
}
public class CompanyConfiguration
: EntityTypeConfiguration<Company>
{
public CompanyConfiguration()
: base()
{
HasKey(p => p.Id);
Property(p => p.Id)
.HasColumnName("Id")
.HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity)
.IsRequired();
Property(p => p.CompanyName)
.HasColumnName("Name")
.IsRequired();
ToTable("Companies");
}
}
public class CountryConfiguration
: EntityTypeConfiguration<Country>
{
/// <summary>
/// Initializes a new instance of the <see cref="CountryConfiguration"/> class.
/// </summary>
public CountryConfiguration()
: base()
{
HasKey(p => p.Id);
Property(p => p.Id)
.HasColumnName("Id")
.HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity)
.IsRequired();
Property(p => p.Code)
.HasColumnName("Code")
.IsRequired();
Property(p => p.Name)
.HasColumnName("Name")
.IsRequired();
ToTable("Countries");
}
}
public class Company
{
public int Id { get; set; }
public string CompanyName { get; set; }
public Country HomeCountry { get; set; }
}
public class Country
{
public int Id { get; set; }
public string Code { get; set; }
public string Name { get; set; }
}
}
The above fails with the following when saving the country: Invalid column name 'HomeCountry_Id
Any help would be very much appreciated!!
Thanks, Paul.
public CompanyConfiguration()
{
//...
HasRequired(x => x.HomeCountry).WithMany()
.Map(x => x.MapKey("HomeCountryId"));
}
We are moving a Web Forms app to MVC3 using Code First against an existing db without any problems. Here are 2 sample Models and the DbContext I'm using. prDepartments & prCategories map to tables in the db and ApplicationDBContext matches the connection string in Web.config
The DeptID field in prCategory is a Foreign Key to prDepartment - Everything works great
public class prCategory
{
[Key]
public int CatgID { get; set; }
public int DeptID { get; set; }
[Required(ErrorMessage="Category Description Is Required")]
[DisplayName("Desc Name")]
[CssClass("ui-Field-Name")]
public string Description { get; set; }
public string Route { get; set; }
public string OrderBy { get; set; }
public virtual prDepartment Department { get; set; }
public virtual List<prProduct> prProducts { get; set; }
}
public class prDepartment
{
[Key]
public int DeptID { get; set; }
[Required(ErrorMessage = "Department Description Is Required")]
[RequiredMessage("This is the Required Message")]
public string Description { get; set; }
public string Route { get; set; }
public string OrderBy { get; set; }
public virtual List<prCategory> prCategories { get; set; }
}
public class ApplicationDbContext : DbContext
{
public DbSet<prDepartment> prDepartments { get; set; }
public DbSet<prCategory> prCategories { get; set; }
public DbSet<prProduct> prProducts { get; set; }
}
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