访问链接到主键的第二列外键值答案

【问题标题】：Access the 2nd column foreign key value linked to primary key访问链接到主键的第二列外键值
【发布时间】：2023-03-18 20:24:02
【问题描述】：

我有一个表Batches，其中DispatchBy 和DispatchTo 链接到一个主键表：Users。

在视图中，我使用以下代码从 Users 表中获取 DispatchBy UserName。如何获得DispatchTo UserName？

 @foreach ( var item in Model.Batches)
                {
                    <tr>
                        <th>@item.User.UserName</th>
                        <th>@item.DispatchByStatus</th>
                        <th>@item.DispatchByTimestamp</th>
                        <th>@item.User1.UserName</th>
                        <th>@item.DispatchToStatus</th>
                        <th>@item.DispatchToTimestamp</th>
                    </tr>
                }

表格：批次

CREATE TABLE [dbo].[Batches] (
    [BTransactionID]      INT          IDENTITY (1, 1) NOT NULL,
    [BatchID]             INT          NULL,
    [TaxPayerTIN]         VARCHAR (9)  NOT NULL,
    [Qty]                 INT          NOT NULL,
    [DispatchBy]          INT          NOT NULL,
    [DispatchByStatus]    VARCHAR (11) NOT NULL,
    [DispatchByTimestamp] DATETIME     NOT NULL,
    [DispatchTo]          INT          NULL,
    [DispatchToStatus]    VARCHAR (11) NULL,
    [DispatchToTimestamp] DATETIME     NULL,
    CONSTRAINT [PK_Batch] PRIMARY KEY CLUSTERED ([BTransactionID] ASC),
    CONSTRAINT [FK_Batches_Users1] FOREIGN KEY ([DispatchTo]) REFERENCES [dbo].[Users] ([UserID]),
    CONSTRAINT [FK_Batches_Users] FOREIGN KEY ([DispatchBy]) REFERENCES [dbo].[Users] ([UserID])
);

表格：用户

CREATE TABLE [dbo].[Users] (
    [UserID]           INT           IDENTITY (1, 1) NOT NULL,
    [UserName]         VARCHAR (255) NOT NULL,
    [UserEmail]        VARCHAR (255) NOT NULL,
    [UserPassword]     VARCHAR (255) NOT NULL,
    [UserPasswordSalt] VARCHAR (255) NULL,
    [UserRoleID]       INT           NOT NULL,
    [DepartmentID]     INT           NOT NULL,
    [UserCreated]      DATETIME      NOT NULL,
    [UserStatus]       VARCHAR (11)  NOT NULL,
    CONSTRAINT [PK_Users_1] PRIMARY KEY CLUSTERED ([UserID] ASC),
    CONSTRAINT [FK_Users_Departments] FOREIGN KEY ([DepartmentID]) REFERENCES [dbo].[Departments] ([DepartmentID]),
    CONSTRAINT [FK_Users_Roles] FOREIGN KEY ([UserRoleID]) REFERENCES [dbo].[Roles] ([RoleID])
);

模型：Batch.cs

public partial class Batch
{
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
    public Batch()
    {
        this.Collections = new HashSet<Collection>();
    }

    public int BTransactionID { get; set; }
    public Nullable<int> BatchID { get; set; }
    public string TaxPayerTIN { get; set; }
    public int Qty { get; set; }
    public int DispatchBy { get; set; }
    public string DispatchByStatus { get; set; }
    public System.DateTime DispatchByTimestamp { get; set; }
    public Nullable<int> DispatchTo { get; set; }
    public string DispatchToStatus { get; set; }
    public Nullable<System.DateTime> DispatchToTimestamp { get; set; }

    public virtual User User { get; set; }
    public virtual User User1 { get; set; }

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<Collection> Collections { get; set; }
}

【问题讨论】：

<th>@item.User.UserName</th> ?我建议将Batch 类中的User 和User1 属性重命名为有意义的名称（例如：DispatchToUser、DispatchByUser），让您的生活更轻松。

标签： c# asp.net-mvc entity-framework linq

【解决方案1】：

它现在正在工作。我不知道我做了什么以及曾经做过什么，但它现在起作用了。

【讨论】：