entity-framework-migrations - 当 key 位于基类中时，EF 迁移 DropForeignKey 失败

Question

我正在尝试为 EF 5.0.0-rc 代码优先类库更新我的数据模型。 Up() 方法中的第一个命令是

DropForeignKey("dbo.ChileInventory", new[] { "LotInventoryItemTypeId", "ChileProductId" }, "dbo.ChileProducts");

但我收到 SqlException: 'FK_dbo.ChileInventory_dbo.ChileProducts_LotInventoryItemTypeId_ChileProductId' 不是约束。无法删除约束。

我认为错误的原因是由于我的 ChileProducts 类从其基类中获取了它的关键属性。由于接受主列名称的 DropForeignkey 方法没有重载，我相信 EF 无法确定要删除的正确约束。我还应该指出，异常消息中显示的约束名称与数据库中的约束名称不匹配(因此出现错误......)

您将在下面找到数据模型和迁移方法。但首先简要说明一下迁移背后的变化性质:InventoryBase 类的每个派生类都通过 InventoryTypeId 和 [InventoryTypeSpecific]ProductId 的复合键定义产品类型。例如，ChileInventory 会将其特定的智利类型标识为 InventoryItemTypeId = [ChileInventoryTypeId] 和 ChileProductId = [ChileProductId]。 PackagingInventory 会将其包装类型标识为 InventoryItemTypeId = [PackagingInventoryTypeId] 和 PackagingProductId = [PackagingProductId]。等等。

我正在努力推出的模型更改是将 [InventoryTypeSpecific]ProductId 从每个 InventoryBase 衍生品提升到基础。这将导致所有 InventoryBase 派生对象共享一个公共(public) ProductId 属性，该属性与 InventoryItemTypeId 一起可以实现从 InventoryBase 到 ProductBase 的导航；这在以前的模型中是不可能的。

提前感谢您的建议和考虑。
——文尼

数据模型

智利产品

public abstract class ProductBase
{
    [Key]
    [Column(Order = 0)]
    public virtual int InventoryItemTypeId { get; set; }

    [Key]
    [Column(Order = 1)]
    public virtual int Id { get; set; }

    [StringLength(150)]
    public virtual string Name { get; set; }

    [ForeignKey("InventoryItemTypeId")]
    public virtual InventoryItemType InventoryItemType { get; set; }

    public virtual bool IsActive { get; set; }
}
public class ChileProduct : ProductBase
{
    public virtual int ChileTypeId { get; set; }

    [ForeignKey("ChileTypeId")]
    public virtual ChileType ChileType { get; set; }
}

智利库存

public abstract class InventoryBase
{
    [Key]
    [Column(Order = 0, TypeName = "Date")]
    public virtual DateTime DateCreated { get; set; }

    [Key]
    [Column(Order = 1)]
    public virtual int Sequence { get; set; }

    [Key]
    [Column(Order = 2)]
    public virtual int LotInventoryItemTypeId { get; set; }

    [Column(TypeName = "Date")]
    public virtual DateTime LotDateCreated { get; set; }

    public virtual int LotSequence { get; set; }

    public virtual int ProductId { get; set; }

    [ForeignKey("LotInventoryItemTypeId, LotDateCreated, LotSequence")]
    public virtual Lot Lot { get; set; }

    [ForeignKey("LotInventoryItemTypeId")]
    public virtual InventoryItemType ItemType { get; set; }

    public virtual ICollection<InventoryQuantityByLocation> QuantitiesByLocation { get; set; }

    [ForeignKey("LotInventoryItemTypeId, ProductId")]
    public virtual ProductBase ProductBase { get; set; }
}

public class ChileInventory : InventoryBase
{
    [Column(TypeName = "Date")]
    public virtual DateTime? ProductionBatchDateCreated { get; set; }

    public virtual int? ProductionBatchSequence { get; set; }

    public virtual int PackagingInventoryItemTypeId { get; set; }

    public virtual int PackagingProductId { get; set; }

    [ForeignKey("ProductionBatchDateCreated, ProductionBatchSequence")]
    public virtual ProductionBatch ProductionBatch { get; set; }

    [ForeignKey("LotInventoryItemTypeId, ProductId")]
    public virtual ChileProduct ChileProduct { get; set; }

    [ForeignKey("PackagingInventoryItemTypeId, PackagingProductId")]
    public virtual PackagingProduct PackagingProduct { get; set; }

}

移民

public override void Up()
    {
        DropForeignKey("dbo.ChileInventory", new[] { "LotInventoryItemTypeId", "ChileProductId" }, "dbo.ChileProducts");
        DropForeignKey("dbo.PackagingInventory", new[] { "LotInventoryItemTypeId", "PackageId" }, "dbo.PackagingProducts");
        DropForeignKey("dbo.AdditiveInventory", new[] { "LotInventoryItemTypeId", "AdditiveProductId" }, "dbo.AdditiveProducts");
        DropIndex("dbo.ChileInventory", new[] { "LotInventoryItemTypeId", "ChileProductId" });
        DropIndex("dbo.PackagingInventory", new[] { "LotInventoryItemTypeId", "PackageId" });
        DropIndex("dbo.AdditiveInventory", new[] { "LotInventoryItemTypeId", "AdditiveProductId" });
        AddColumn("dbo.Inventory", "ProductId", c => c.Int(nullable: false));
        AddForeignKey("dbo.Inventory", new[] { "LotInventoryItemTypeId", "ProductId" }, "dbo.AdditiveProducts", new[] { "InventoryItemTypeId", "Id" });
        AddForeignKey("dbo.Inventory", new[] { "LotInventoryItemTypeId", "ProductId" }, "dbo.AdditiveProducts", new[] { "InventoryItemTypeId", "Id" });
        AddForeignKey("dbo.Inventory", new[] { "LotInventoryItemTypeId", "ProductId" }, "dbo.AdditiveProducts", new[] { "InventoryItemTypeId", "Id" });
        AddForeignKey("dbo.Inventory", new[] { "LotInventoryItemTypeId", "ProductId" }, "dbo.AdditiveProducts", new[] { "InventoryItemTypeId", "Id" });
        CreateIndex("dbo.Inventory", new[] { "LotInventoryItemTypeId", "ProductId" });
        CreateIndex("dbo.Inventory", new[] { "LotInventoryItemTypeId", "ProductId" });
        CreateIndex("dbo.Inventory", new[] { "LotInventoryItemTypeId", "ProductId" });
        CreateIndex("dbo.Inventory", new[] { "LotInventoryItemTypeId", "ProductId" });
        DropColumn("dbo.ChileInventory", "ChileProductId");
        DropColumn("dbo.PackagingInventory", "PackageId");
        DropColumn("dbo.AdditiveInventory", "AdditiveProductId");
    }

    public override void Down()
    {
        AddColumn("dbo.AdditiveInventory", "AdditiveProductId", c => c.Int(nullable: false));
        AddColumn("dbo.PackagingInventory", "PackageId", c => c.Int(nullable: false));
        AddColumn("dbo.ChileInventory", "ChileProductId", c => c.Int(nullable: false));
        DropIndex("dbo.Inventory", new[] { "LotInventoryItemTypeId", "ProductId" });
        DropIndex("dbo.Inventory", new[] { "LotInventoryItemTypeId", "ProductId" });
        DropIndex("dbo.Inventory", new[] { "LotInventoryItemTypeId", "ProductId" });
        DropIndex("dbo.Inventory", new[] { "LotInventoryItemTypeId", "ProductId" });
        DropForeignKey("dbo.Inventory", new[] { "LotInventoryItemTypeId", "ProductId" }, "dbo.AdditiveProducts");
        DropForeignKey("dbo.Inventory", new[] { "LotInventoryItemTypeId", "ProductId" }, "dbo.AdditiveProducts");
        DropForeignKey("dbo.Inventory", new[] { "LotInventoryItemTypeId", "ProductId" }, "dbo.AdditiveProducts");
        DropForeignKey("dbo.Inventory", new[] { "LotInventoryItemTypeId", "ProductId" }, "dbo.AdditiveProducts");
        DropColumn("dbo.Inventory", "ProductId");
        CreateIndex("dbo.AdditiveInventory", new[] { "LotInventoryItemTypeId", "AdditiveProductId" });
        CreateIndex("dbo.PackagingInventory", new[] { "LotInventoryItemTypeId", "PackageId" });
        CreateIndex("dbo.ChileInventory", new[] { "LotInventoryItemTypeId", "ChileProductId" });
        AddForeignKey("dbo.AdditiveInventory", new[] { "LotInventoryItemTypeId", "AdditiveProductId" }, "dbo.AdditiveProducts", new[] { "InventoryItemTypeId", "Id" });
        AddForeignKey("dbo.PackagingInventory", new[] { "LotInventoryItemTypeId", "PackageId" }, "dbo.PackagingProducts", new[] { "InventoryItemTypeId", "Id" });
        AddForeignKey("dbo.ChileInventory", new[] { "LotInventoryItemTypeId", "ChileProductId" }, "dbo.ChileProducts", new[] { "InventoryItemTypeId", "Id" });
    }

Answer 1

这是我发现的一种解决方法:

使用包含参数 principalName 和 name 的 DropForeignKey 重载——在这种情况下意味着 约束 姓名!它有点脆弱，因为它需要预先了解约束名称，但它可以按预期工作。