c# - 三个类的多对多关系

Question

一开始我不得不说我不知道​​它是否一定是多对多的关系

假设我有三个类(class):

User-detalis，其中包含一些基本的用户信息，如地区、城市

public class UserDetails
{
  public int Id{get;set;}
  public string City{get;set;}
  public strng Region{get;set;}
}

下一个类是 UserDetailsDictionary

public class UserDetailsDictionary
{
  public int Id{get;set;}
  public string Name{get;set;}
  public string DetailsType{get;set;}
 }

此类将包含如下值:

Name = "football", detailsType="interests",
Name = "basketball", detailsType="interests",
Name = "brown", detailsType="eyes",
Name = "green", detailsType="eyes"

最后一个类应该包含有关将 userDetails 与 Dictionary 和 Values 连接起来的信息:

 public class JoiningClass
   {
     public UserDetails UserDetails{get;set;}
     public UserDetailsDictionary DictionaryItem{get;set;}
     public bool Value{get;set;}
   }

这个类中的值应该是这样的:

(1,1,0)
(1,1,1)(first user like basketball)
(1,2,0)(first user does not have brown eyes)
(2,1,1) (second user likes football)

在代码中我想通过两种方式检查值，我的意思是:

UserDetailsDictionary type;
...
var val1 = _dbContext.UserDetails.Where(x=> x.DictionaryItem.Id == type.Id).Value;

从其他方面来看

UserDetails ud;
...
var allDetailsOfUser = _dbContext.UserDetailsDictionary.ToArray();

另外，假设我想找到所有棕色眼睛的用户 (userDetails):

var dictionaryItem = _dbContext.UserDetailsDictionary.Where(x=>x.Name == "eyesColor").SingleOrDefault();

var userDetails = _dbContext.JoiningClass...?

我应该如何创建这些类？如何在 DbContext 类中创建与 Entity Framework (核心 2.0)的正确关系？

Answer 1

让我知道这是否适合你

我会建议您将这些表标准化为

1.] 第一个模型和表格列

public class UserDetails
{
  public int UserId{get;set;}
  public string UserName{get;set;}
  public string City{get;set;}
  public strng Region{get;set;}
}

2.] 第二个模型和表列

public class UserDetailsDictionary
{
  public int DictId{get;set;}
  public string InterestName{get;set;}
  public string DetailsType{get;set;}
 }

3.]第三张表存储数据

public class UserData
{
  public int UserId{get;set;}
  public int DictonaryId{get;set;}
  public bool _value {get;set;}
 }

我假设数据存储在数据库中，正如您在问题中显示的那样

(1,1,0)

(1,1,1)(first user like basketball)

(1,2,0)(first user does not have brown eyes)

(2,1,1) (second user likes football)

现在让我们举一个例子

(2,1,1) (second user likes football)

ID为2的用户有

Blockquote

对足球的兴趣(id 为 1 的兴趣)

现在你可以从 api 返回一个匿名类型

var m =(from data in _dbContext.UserData
Join details in _dbContext.UserDetails on data.UserID equals details.UserID
Join dict in _dbContext.UserDetailsDictionary on data.DictionaryID equals dict.DictID 
//where Condition if required 
select new {
UserName=details.UserName,
Interest= dict.IntersetName,
//_value=true/false 
}
).ToList();

除了 Annonymous Type，您还可以将 strongly Type Model 作为 Json 返回