實體框架6無法創建外鍵

Question

我正在編寫一個使用EF 6遷移引擎來處理數據庫創建的應用程序。 使用CSharpMigrationCodeGenerator類，我在將由DbMigrator處理的遷移中構建了一個類庫程序集。 它工作正常，但使用外鍵出現此錯誤：

Exception Details: System.Data.Entity.Migrations.Infrastructure.MigrationsException: The Foreign Key on table 'dbo.Tabellina' with columns 'Tabella_Id' could not be created because the principal key columns could not be determined. Use the AddForeignKey fluent API to fully specify the Foreign Key.

遷移代碼是這樣的：

namespace AppMig.Migrations
{
    using System;
    using System.Data.Entity.Migrations;

    public partial class CreateTables: DbMigration
    {
        public override void Up()
        {
            CreateTable(
                "dbo.Tabella",
                c => new
                    {
                        Id = c.Int(nullable: false, identity: true),
                        FromDate = c.DateTime(),
                        Todate = c.DateTime(),
                        campotabella = c.String(maxLength: 50),
                    })
                .Index(t => t.FromDate, name: "tabella_fromdate_index")
                .Index(t => t.Todate, name: "tabella_todate_index");

            AddPrimaryKey("dbo.Tabella", "Id", name: "tabella_id_index");
            CreateTable(
                "dbo.Tabellina",
                c => new
                    {
                        Id = c.Int(nullable: false, identity: true),
                        FromDate = c.DateTime(),
                        Todate = c.DateTime(),
                        campotabellina = c.String(maxLength: 50),
                        Tabella_Id = c.Int(nullable: false),
                    })
                .ForeignKey("dbo.Tabella", t => t.Tabella_Id, cascadeDelete: true)
                .Index(t => t.FromDate, name: "tabellina_fromdate_index")
                .Index(t => t.Todate, name: "tabellina_todate_index")
                .Index(t => t.Tabella_Id);

            AddPrimaryKey("dbo.Tabellina", "Id", name: "tabellina_id_index");
        }

        public override void Down()
        {
            DropIndex("dbo.Tabellina", new[] { "Tabella_Id" });
            DropForeignKey("dbo.Tabellina", "Tabella_Id", "dbo.Tabella");
            DropIndex("dbo.Tabellina", "tabellina_todate_index");
            DropIndex("dbo.Tabellina", "tabellina_fromdate_index");
            DropPrimaryKey("dbo.Tabellina", name: "tabellina_id_index");
            DropTable("dbo.Tabellina");
            DropIndex("dbo.Tabella", "tabella_todate_index");
            DropIndex("dbo.Tabella", "tabella_fromdate_index");
            DropPrimaryKey("dbo.Tabella", name: "tabella_id_index");
            DropTable("dbo.Tabella");
        }
    }
}

這是行不通的，但是，如果我創建僅添加外鍵的第二次遷移（當已經創建了兩個表時），則它可以工作。 由於應用程序的結構，對我來說創建第二個遷移真的很困難，因此我需要解決這個難題。

Answer 1

取自原始說明 ，是否有原因不能將.PrimaryKey（t => t.Id）用作主要CreateTable方法的一部分？