如何使用 Entity Framework 连接两个表

Question

控制器：

public ActionResult Index()
{
        var Cs = new List<Customer>();

        using (JoinEntities db = new JoinEntities())
        {
            Cs = (from p in db.Customers
                  join e in db.Orders on p.ID equals e.Customer_id
                  where p.Name == "Rama"
                  select p).ToList();
        }

        return View(Cs);
}

查看：

@model IEnumerable<JOIN.Models.Customer>
@{
    ViewBag.Title = "Home Page";
}
<table class="table table-condensed table-hover">
   <thead>
     <tr>
        <td>First Name</td>
        <td>salary</td>
        <td>age</td>
        <td>amount</td>
    </tr>
   </thead>
   <tbody>
   @foreach (var per in Model)
   {
     <tr>
        <td>@per.ID</td>
        <td>@per.Name</td>
        <td>@per.Age</td>
        <td>@per.Amount</td>
     </tr>
    }
</tbody>
</table>

上面的代码视图是否只包含一个 table 列我怎样才能获得 customer table 中的其他 table 列 id 是主键和订单 table customer_id 是外键

customer table: id, name, age, salary 列
order table: oid, date, customer_id, amount columns

Answer 1

您需要创建另一个模型，例如

class MyModel{
     public string Name{get;set;}
     public DateTime Date {get;set;}
}

并在 select 查询中更改：

var Cs = new List<MyModel>();

using (JoinEntities db = new JoinEntities())
        {
            Cs = (from p in db.Customers
                  join e in db.Orders on p.ID equals e.Customer_id
                  where p.Name == "Rama"
                  select new MyModel {
                     Name = p.Name,
                     Date = e.date
                  }).ToList();
        }

Answer 2

如下创建另一个视图模型

public class CustomerOrderViewModel
    {
        public int CustomerId { get; set; }
        public string Name { get; set; }
        public int Age { get; set; }
        public double  Salary { get; set; }

        public int OrderId { get; set; }
        public DateTime Date { get; set; }
        public double  Amount { get; set; }
    }

并如下更新您的 Index 方法

public ActionResult Index()
    {
        using (JoinEntities db = new JoinEntities())
        {
            var customerOrderList = (from p in db.Customers
                  join e in db.Orders on p.ID equals e.Customer_id
                  where p.Name == "Rama"
                  select new CustomerOrderViewModel {
                      CustomerId = p.Id,
                      Name = p.Name,
                      Age= p.Age,
                      Salary = p.Salary,
                      OrderId= e.Id,
                      Date= e.Date,
                      Amount = e.Amount
                  }).ToList();
            return View(customerOrderList);
        }        
    }

并将视图的视图模型更改为

@model IEnumerable<JOIN.Models.CustomerOrderViewModel>

如何使用 Entity Framework 连接两个表

How to join two tables using Entity Framework

asp.net-mvc

entity-framework-6