错误：每个表中的列名必须是唯一的

Question

我在执行 update-database 时收到错误，其中指出：“每个表中的列名称必须是唯一的。表 'dbo.OrderForms' 中的列名称 'OrderRecieveDate' 被指定多次。”我已经尝试了所有我能想到的方法来修复它，但到目前为止还没有任何结果。以前，我可以通过我创建的网站从表中添加/更新/删除行，但现在该功能似乎不起作用。此时我什至无法让数据库添加我的种子数据。

我的上下文/模型文件：

public class OrderFormContext : DbContext
{
    public DbSet<OrderForm> OrderForms { get; set; }
}

public class OrderForm 
{
    [Key, Display(Name= "Order ID" )]
    [ScaffoldColumn(false)]
    public int OrderID { get; set; }


    private DateTime _date = DateTime.Today;
    [Display(Name = "Date Posted")]
    [ScaffoldColumn(false)]
    public DateTime OrderPostDate
    {
        get { return _date; }
        set { _date = value; }
    }

    [EnumDataType(typeof(PersonReqID)),Display(Name = "Person Requesting")]
    public PersonReqID PersonReq { get; set; }

    [StringLength(100), Display(Name = "Grant")]
    public string GrantID { get; set; }

    [StringLength(10000), Display(Name = "Product Description"), DataType(DataType.MultilineText)]
    public string ItemDescription { get; set; }

    [StringLength(100), Display(Name = "Quantity")]
    public string ItemQuantity { get; set; }

    [StringLength(100), Display(Name = "Price")]
    public string UnitPrice { get; set; }

    [StringLength(100), Display(Name = "Company")]
    public string CompanyID { get; set; }

    [StringLength(100), Display(Name = "Catalog #")]
    public string CatalogNum { get; set; }

    [ScaffoldColumn(false)]
    [Range(typeof(DateTime), "1/1/1111", "1/1/3000", ErrorMessage = "Please provide a date.")]
    [DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:d}")]
    public DateTime OrderMadeDate { get; set; }

    [ScaffoldColumn(false)]
    [Range(typeof(DateTime), "1/1/1111", "1/1/3000", ErrorMessage = "Please provide a date.")]
    [DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:d}")]
    public DateTime OrderRecieveDate { get; set; }

    [ScaffoldColumn(false)]
    [EnumDataType(typeof(PersonRecID)), Display(Name = "Person Recieving")]
    public PersonRecID PersonRec { get; set; }

    [ScaffoldColumn(false)]
    [StringLength(100), Display(Name = "Item Location")]
    public string ItemLoc { get; set; }
}

我的Configuration.cs文件：

context.OrderForms.AddOrUpdate(
                new OrderForm
                {
                    OrderID=1,
                    OrderPostDate=DateTime.Now,
                    PersonReq=PersonReqID.Jake,
                    GrantID="NASA",
                    ItemDescription="Grenades",
                    ItemQuantity="100",
                    UnitPrice="1.50",
                    CompanyID="Grenades UNLMTD",
                    CatalogNum="G1001",
                    PersonRec=PersonRecID.Ajit,
                    ItemLoc="Freezer"
                }

                ); 

         context.SaveChanges();

最后是我的 xxxxxxx_initial.cs 迁移文件：

public override void Up()
    {
        AddColumn("dbo.OrderForms", "OrderRecieveDate", c =>
         c.DateTime(nullable: false, defaultValue: new DateTime(1000, 1, 1)));
        AddColumn("dbo.OrderForms", "OrderMadeDate", d =>
        d.DateTime(nullable: false, defaultValue: new DateTime(1000, 1, 1)));

    }

    public override void Down()
    {
        DropColumn("dbo.OrderForms", "OrderRecieveDate");
        DropColumn("dbo.OrderForms", "OrderMadeDate");

    }

我对网页设计非常陌生，所以我只是总结我认为可能导致问题的所有内容。这是我的 OrderForms.dbo 文件的表定义。

CREATE TABLE [dbo].[OrderForms] (
[OrderID]          INT            IDENTITY (1, 1) NOT NULL,
[GrantID]          NVARCHAR (100) NULL,
[ItemDescription]  NVARCHAR (MAX) NULL,
[ItemQuantity]     NVARCHAR (100) NULL,
[UnitPrice]        NVARCHAR (100) NULL,
[CompanyID]        NVARCHAR (100) NULL,
[CatalogNum]       NVARCHAR (100) NULL,
[OrderDate]        NVARCHAR (100) NULL,
[ItemLoc]          NVARCHAR (100) NULL,
[PersonReq]        INT            DEFAULT ((0)) NULL,
[PersonRec]        INT            DEFAULT ((0)) NULL,
[OrderPostDate]    DATETIME       DEFAULT ('1900-01-01T00:00:00.000') NULL,
[OrderRecieveDate] DATETIME       DEFAULT ('2013-01-01T00:00:00.000') NULL,
[OrderMadeDate]    DATETIME       DEFAULT ('2013-01-01T00:00:00.000') NULL,
CONSTRAINT [PK_dbo.OrderForms] PRIMARY KEY CLUSTERED ([OrderID] ASC)

）；

任何帮助将不胜感激。我似乎无法弄清楚该列是如何创建两次的。我尝试删除数据库和以前的迁移并执行“enable-migrations -forced”并从那里重新启动，但无济于事。这可能与我缺乏 EF 背景知识有关。预先感谢您的帮助！

Answer 1

所以我可能会误解你所拥有的内容，但是你不要在定义中创建一次列：

CREATE TABLE [dbo].[OrderForms] (
[OrderID]          INT            IDENTITY (1, 1) NOT NULL,
[GrantID]          NVARCHAR (100) NULL,
[ItemDescription]  NVARCHAR (MAX) NULL,
[ItemQuantity]     NVARCHAR (100) NULL,
[UnitPrice]        NVARCHAR (100) NULL,
[CompanyID]        NVARCHAR (100) NULL,
[CatalogNum]       NVARCHAR (100) NULL,
[OrderDate]        NVARCHAR (100) NULL,
[ItemLoc]          NVARCHAR (100) NULL,
[PersonReq]        INT            DEFAULT ((0)) NULL,
[PersonRec]        INT            DEFAULT ((0)) NULL,
[OrderPostDate]    DATETIME       DEFAULT ('1900-01-01T00:00:00.000') NULL,
[OrderRecieveDate] DATETIME       DEFAULT ('2013-01-01T00:00:00.000') NULL,
[OrderMadeDate]    DATETIME       DEFAULT ('2013-01-01T00:00:00.000') NULL,
CONSTRAINT [PK_dbo.OrderForms] PRIMARY KEY CLUSTERED ([OrderID] ASC)

然后尝试再次创建它们

public override void Up()
    {
        AddColumn("dbo.OrderForms", "OrderRecieveDate", c =>
         c.DateTime(nullable: false, defaultValue: new DateTime(1000, 1, 1)));
        AddColumn("dbo.OrderForms", "OrderMadeDate", d =>
        d.DateTime(nullable: false, defaultValue: new DateTime(1000, 1, 1)));

    }

如果您需要一些故障排除建议，您可以使用 sys.tables 和 sys.columns 来查找值，并在添加列上使用 IF NOT EXISTS。

这需要一些修改，但这可能足以让您继续下去。

  string columnToAdd = " ADD [" + columnList[i] + "] " + columnDataTypeList[i];
  string alterTableSQL = @"ALTER TABLE " + DestinationTbl + columnList[i];
  string columnMakerSQL += @"IF NOT EXISTS ( SELECT * FROM   sys.columns WHERE  object_id = OBJECT_ID(N'" + DestinationTbl
                                + @"') AND name = '" + columnList[i]
                                + @"' ) BEGIN "
                                + alterTableSQL
                                + @" END ";