类关系，表参考

Question

我想在C＃MVC和SQL中向你们提一点帮助。这是我的问题。我有2个表Tbl_Master_Personnel_Info和Tbl_Ref_Gender

第一个表格包含以下字段：

• PERSONID
• 名字
• 姓
• GenderId

第二张表有以下恶魔：

• GenderId
• GenderName

我有这个类PersonnelInfo和Gender

public class PersonnelInfo(){
public int PersonId {get; set;}
public string LastName {get; set;}
public string FirstName {get; set;}
public int GenderId {get; set;}
}

public class Gender(){
public int GenderId {get; set;}
public string GenderName {get; set;}
}

---

我已经列出了人事信息，但我希望GenderId从此表的数据显示为GenderName Tbl_Ref_Gender

Current result
------------------------------------------
1 | FirLastName | FirFirstName | FirMI | 10
2 | SecLastName | SecFirstName | SecMI | 20

How can I achieve this result.
------------------------------------------
1 | FirLastName | FirFirstName | FirMI | Male
2 | SecLastName | SecFirstName | SecMI | Female

提前谢谢。

Answer 1

以下是您可以使用的示例代码。

using System;
using System.ComponentModel.DataAnnotations;
using System.Linq;

namespace TestConsole
{
    public class PersonnelInfo
    {
        [Required]
        [Key]
        public int PersonId { get; set; }
        public string LastName { get; set; }
        public string FirstName { get; set; }

        public int GenderId { get; set; }
        [Required]
        public Gender Gender { get; set; }
    }

    public class Gender
    {
        [Key]
        public int GenderId { get; set; }
        public string GenderName { get; set; }
    }



    internal class Program
    {
        public TestConsoleDbContext MyDbContext { get; set; }

        public Program()
        {
            MyDbContext = new TestConsoleDbContext();
        }

        private static void Main(string[] args)
        {

            var program = new Program();
            program.CreateData();

            var records = from p in program.MyDbContext.PersonnelInfos
                          select new { p.FirstName, p.LastName, p.Gender.GenderName };

            foreach (var r in records)
            {
                Console.WriteLine("Name: {0} {1} Gender: {2}", r.FirstName, r.LastName, r.GenderName);
            }

            Console.ReadLine();


        }

        private void CreateData()
        {
            var record = new PersonnelInfo() { FirstName = "First Name 1", LastName = "Last Name 1", GenderId = GetGenderIdbyName("male") };
            var record1 = new PersonnelInfo() { FirstName = "First Name 2", LastName = "Last Name 2", GenderId = GetGenderIdbyName("female") };

            MyDbContext.PersonnelInfos.Add(record);
            MyDbContext.PersonnelInfos.Add(record1);
            MyDbContext.SaveChanges();
        }

        private int GetGenderIdbyName(string genderName)
        {
            var genderRecord = (from g in MyDbContext.Genders
                                where g.GenderName.Equals(genderName, StringComparison.CurrentCultureIgnoreCase)
                                select g).FirstOrDefault();

            var genderId = 0;


            if (genderRecord == null)
            {
                var gender = new Gender() { GenderName = genderName };

                MyDbContext.Genders.Add(gender);
                MyDbContext.SaveChanges();
                genderId = gender.GenderId;

            }
            else
            {
                genderId = genderRecord.GenderId;
            }

            return genderId;

        }
    }
}
using System.Data.Entity;

namespace TestConsole
{
    internal class TestConsoleDbContext : DbContext
    {
        public IDbSet<PersonnelInfo> PersonnelInfos { get; set; }
        public IDbSet<Gender> Genders { get; set; }
    }
}

Answer 2

您可以通过以下方式对关键GenderId上的两个表执行连接。

IQueriable result = 
    from p in personnelList
    join g in GenderLIst on p.GenderId=g.GenderId
    select new 
    {
        PersonId = p.PersonId,
        FullName = p.FirstName + " " + p.LastName,
        GenderId = p.GenderId,
        GenderName = g.GenderName
    };
 }