Question

我有以下模型：

public class Transfer
{
    public Article Article { get; set; }
    public Branch BranchFrom { get; set; }
    public Branch BranchTo { get; set; }
    public User User { get; set; }
}

 public class Article
{
    public int Id{ get; set; }
    public string Description { get; set; }
}

 public class Branch
{
    public int Id { get; set; }
    public string Address { get; set; }
}

 public class User
{
    public int Id { get; set; }
    public string Name { get; set; }
}

我需要获取特定用户进行的所有转移的列表，并加载其所有相关实体（BranchFrom，BranchTo，Article，User）。

在EF 6中，我可以使用以下代码轻松做到这一点：

_dbContext.Transfer.Include(x=>x.BranchFrom).Include(x=>x.BranchTo).Include(x=>x.Article).Include(x=>x.User).Where(x=>x.User.Id == userId).ToListAsync();

鉴于在EF Core 2.1中必须定义联接表，因此我将它们添加如下：

public class TransferUser
{
    public int TransferId { get; set; }
    public int UserId { get; set; }
    public Transfer Transfer { get; set; }
    public User User { get; set; }
}

 public class TransferArticle
{
    public int TransferId { get; set; }
    public int ArticleId { get; set; }
    public Transfer Transfer { get; set; }
    public Article Article { get; set; }
}

 public class TransferBranchFrom
{
    public int TransferId { get; set; }
    public int BranchId { get; set; }
    public Transfer Transfer { get; set; }
    public Branch Branch { get; set; }
}

 public class TransferBranchTo
{
    public int TransferId { get; set; }
    public int BranchId { get; set; }
    public Transfer Transfer { get; set; }
    public Branch Branch { get; set; }
}

因此，我将Transfer模型修改为：

public class Transfer
{
    public TransferArticle TransferArticle { get; set; }
    public TransferBranch TransferBranchFrom { get; set; }
    public TransferBranch TransferBranchTo { get; set; }
    public TransferUser TransferUser { get; set; }
}

现在我不知道查询的方式。

我这样做是可行的，但是只加载传输和用户

_dbContext.Transfer.Include(x=>x.TransferUser).Where(x=>x.TransferUser.UserId == userId).ToListAsync();

当我添加另一个表时，它不起作用并引发异常：

_dbContext.Transfer.Include(x=>x.TransferUser).Include(x=>x.TransferBranchFrom).Where(x=>x.TransferUser.UserId == userId).ToListAsync();

在这种情况下，我找不到任何有关如何加载所有实体的示例

EF核心2.1。使用连接表加载嵌套实体

0 个答案: