Create composite in multiple foreign key using entity framework - entity-framework

Question

In multi tenant application, we can force the ID that is in another tenant in dropdown for example
My models is:
public class Tenant
{
public int Id { get; set; }
public string Name { get; set; }
}
public class Customer
{
public int Id { get; set; }
public int TenantId { get; set; }
public string Name { get; set;}
}
public class Order
{
public int Id { get; set; }
public int CustomerId { get; set; }
public int TenantId { get; set; }
public float Price { get; set; }
}
this code should generate a table similar to this:
CREATE TABLE tenant (
id INT NOT NULL,
nome VARCHAR(255) NOT NULL,
PRIMARY KEY (id)
);
CREATE TABLE customer (
id INT NOT NULL,
id_tenant INT NOT NULL,
nome VARCHAR(255) NOT NULL,
PRIMARY KEY (id),
FOREIGN KEY (id_tenant) REFERENCES tenant(id),
-- pra ter a FK composta, tem que ter chave composta na tabela de origem
UNIQUE (Id,id_tenant)
);
CREATE TABLE [order] (
id INT NOT NULL,
id_customer INT NOT NULL,
id_tenant INT NOT NULL,
nome VARCHAR(255) NOT NULL,
PRIMARY KEY (id),
FOREIGN KEY (id_customer, id_tenant) REFERENCES customer (id, id_tenant),
FOREIGN KEY (id_tenant) REFERENCES tenant(id)
);
But, how create composite using FLUENT API?
EDIT:
I want to ensure that the CustomerID passed to the Order.cs has the same TenantId
That is, Customer and Order must have the same TenantId

Answer 1

I want to ensure that the CustomerID passed to the Order.cs has the same TenantId
To declare a compound foreign key in the Fludent API is just like declaring a compound primary key. Use an anonymous type.
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations.Schema;
using System.Data.Entity;
using System.Data.Entity.ModelConfiguration;
using System.Data.SqlClient;
using System.Linq;
namespace ConsoleApp8
{
public class Tenant
{
public int Id { get; set; }
public string Name { get; set; }
}
public class Customer
{
public int Id { get; set; }
public int TenantId { get; set; }
public virtual Tenant Tenant {get;set;}
public string Name { get; set; }
}
public class Order
{
public int Id { get; set; }
public int CustomerId { get; set; }
public int TenantId { get; set; }
public Customer Customer { get; set; }
public Tenant Tenant { get; set; }
public decimal Price { get; set; }
}
class Db : DbContext
{
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Tenant>().HasKey(e => e.Id);
modelBuilder.Entity<Customer>().HasKey(e => new { e.TenantId, e.Id });
modelBuilder.Entity<Order>().HasKey(e => new { e.TenantId, e.CustomerId, e.Id });
modelBuilder.Entity<Customer>()
.HasRequired<Tenant>(e => e.Tenant)
.WithMany()
.HasForeignKey(e => e.TenantId);
modelBuilder.Entity<Order>()
.HasRequired<Customer>(e => e.Customer)
.WithMany()
.HasForeignKey(e => new { e.TenantId, e.CustomerId });
modelBuilder.Entity<Order>()
.HasRequired<Tenant>(e => e.Tenant)
.WithMany()
.HasForeignKey(e => e.TenantId)
.WillCascadeOnDelete(false);
}
}
class Program
{
static void Main(string[] args)
{
Database.SetInitializer(new DropCreateDatabaseAlways<Db>());
using (var db = new Db())
{
db.Database.Log = m => Console.WriteLine(m);
db.Database.Initialize(true);
}
Console.WriteLine("Hit any key to exit");
Console.ReadKey();
}
}
}