如何在.NET核心API中设计嵌套类以获得特定的模式？

Question

我是第一次在.NET核心应用程序接口中使用实体框架(使用最新版本的.NET核心)。

目前我有两个课程：

public class Employee
{
    public int Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string Gender { get; set; }
    public DateTime JoinedCompany { get; set; }
    public ICollection<Skill> Skills { get; set; }
}

public class Skill
{
    public int Id { get; set; }
    public string SkillName { get; set; }
}

我还有一个DBContext类，它包含

public DbSet<Employee> Employees { get; set; }
public DbSet<Skill> Skills { get; set; }

我可以用下面的代码来检索它：

public async Task<IReadOnlyList<Employee>> GetEmployeesAsync () {
            return await _context.Employees
            .Include(p => p.Skills)
            .ToListAsync();
        }

现在，我使用实体框架迁移来创建表。使用现有的类，我得到了下面的表和两个表：

(1) "Employees“，列为: Id，FirstName，LastName，Gender，JoinedCompany

(2)“技能”，列为: Id、SkillName、EmployeeId

我用一些数据填充了这些表，并在postman中访问API的一个端点时返回了以下内容：

[
    {
        "firstName": "Jess",
        "lastName": "Turner",
        "gender": "F",
        "joinedCompany": "2018-10-04T00:00:00",
        "skills": [
            {
                "skillName": "T-SQL",
                "id": 1
            },
            {
                "skillName": "Angular",
                "id": 2
            },
            {
                "skillName": "Vue",
                "id": 3
            },
            {
                "skillName": "Redux",
                "id": 4
            }
        ],
        "id": 1
    },
    {
        "firstName": "Olivia",
        "lastName": "Lu",
        "gender": "F",
        "joinedCompany": "2015-03-31T00:00:00",
        "skills": [
            {
                "skillName": "Hadoop",
                "id": 5
            },
            {
                "skillName": "Azure Databricks",
                "id": 6
            },
            {
                "skillName": "Spark",
                "id": 7
            },
            {
                "skillName": "Python",
                "id": 8
            },
            {
                "skillName": "T-SQL",
                "id": 9
            }
        ],
        "id": 2
    },
    {
        "firstName": "Jonah",
        "lastName": "Smythe",
        "gender": "M",
        "joinedCompany": "2020-08-11T00:00:00",
        "skills": [],
        "id": 3
     }
]

现在，我试图弄清楚的是如何设计类，以便在运行时使用实体框架创建数据库，这样我就可以得到三个表：

(1) "Employees“，列为: Id，FirstName，LastName，Gender，JoinedCompany

(1) "EmployeeSkills“，列为: Id，EmployeeId，SkillId

(2)“技能”，列: Id，SkillName

原因是我不想在每次为员工出现"SkillName“字符串时反复存储它。我只想用身份证。这也会改变我上面应用的GetEmployeesAsync方法。谢谢你。

Answer 1

public class Employee
{
    public int Id { get; set; }

    public string FirstName { get; set; }

    public string LastName { get; set; }

    public string Gender { get; set; }

    public DateTime JoinedCompany { get; set; }

    public ICollection<EmployeeSkill> Skills { get; set; } = new HashSet<EmployeeSkill>();
}

public class Skill
{
    public int Id { get; set; }

    public string SkillName { get; set; }

    public ICollection<EmployeeSkill> Emploees { get; set; } = new HashSet<EmployeeSkill>();
}

public class EmployeeSkill
{
    public int EmployeeId { get; set; }

    public Employee Employee { get; set; }

    public int SkillId { get; set; }

    public Skill Skill { get; set; }
}

public class MyDbContext : DbContext
{

    public DbSet<Employee> Employees { get; set; }

    public DbSet<Skill> Skills { get; set; }

    public DbSet<EmployeeSkill> EmployeesSkills { get; set; }
}