更新 EF 核心中一对多关系的数据

Question

我正在尝试更新一个表（FlightClasses），其中多行与表（Flight）具有一对多的关系，但我无法使用更改后的值更新它 谁能帮我解决这个问题

飞行模型类 我想更新与此表中的行链接的其他飞行类表上的行

namespace Airline.Models
{
    public class FlightModel
    {
        public int Id { get; set; }
        public string FlightName { get; set; }
        public string FlightNo { get; set; }
        public string OriginCity { get; set; }
        public string DestinationCity { get; set; }
        public DateTime Departure { get; set; }
        public DateTime Arrival { get; set; }
        public virtual ICollection<FlightClassesModel> FlightClasses { get; set; }
    }
}

FlightClasses 的模型类

namespace Airline.Models
{
    public class FlightClassesModel
    {

        public int FlightClassesModelId { get; set; }
        public type Class { get; set; }
        public int AvailableSeats { get; set; }
        public double Price { get; set; }
        public virtual FlightModel Flight { get; set; }

        public int? FlightId { get; set; }
    }
    public enum type
    {
        Business_Class,
        First_Class,
        Club_Class
    }
}

查看

@model Airline.Models.FlightModel

@{
    ViewData["Title"] = "Edit";
}

<h2>Edit</h2>

<h4>FlightModel</h4>
<hr />
<div class="row">
    <div class="col-md-4">
        <form asp-action="Edit">
            <div asp-validation-summary="ModelOnly" class="text-danger"></div>
            <input type="hidden" asp-for="Id" />
            <div class="form-group">
                <label asp-for="FlightName" class="control-label"></label>
                <input asp-for="FlightName" class="form-control" />
                <span asp-validation-for="FlightName" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="FlightNo" class="control-label"></label>
                <input asp-for="FlightNo" class="form-control" />
                <span asp-validation-for="FlightNo" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="OriginCity" class="control-label"></label>
                <input asp-for="OriginCity" class="form-control" />
                <span asp-validation-for="OriginCity" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="DestinationCity" class="control-label"></label>
                <input asp-for="DestinationCity" class="form-control" />
                <span asp-validation-for="DestinationCity" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="Departure" class="control-label"></label>
                <input asp-for="Departure" class="form-control" />
                <span asp-validation-for="Departure" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="Arrival" class="control-label"></label>
                <input asp-for="Arrival" class="form-control" />
                <span asp-validation-for="Arrival" class="text-danger"></span>
            </div>
            @foreach (var flightClass in Model.FlightClasses)
            {
                <div class="form-group">
                    <label asp-for="@flightClass.Class" class="control-label"></label>
                    <select class="form-control" asp-for="@flightClass.Class"  asp-items="Html.GetEnumSelectList<type>()"></select>
                    <span asp-validation-for="@flightClass.Class" class="text-danger"></span>
                </div>
                <div class="form-group">
                    <label asp-for="@flightClass.AvailableSeats" class="control-label"></label>
                    <input asp-for="@flightClass.AvailableSeats" class="form-control" />
                    <span asp-validation-for="@flightClass.AvailableSeats" class="text-danger"></span>
                </div>
                <div class="form-group">
                    <label asp-for="@flightClass.Price" class="control-label"></label>
                    <input asp-for="@flightClass.Price" class="form-control" />
                    <span asp-validation-for="@flightClass.Price" class="text-danger"></span>
                </div>
            }

            <div class="form-group">
                <input type="submit" value="Save" class="btn btn-default" />
            </div>
        </form>
    </div>
</div>

<div>
    <a asp-action="Index">Back to List</a>
</div>

控制器

public async Task<IActionResult> Edit(int? id)
        {
            if (id == null)
            {
                return NotFound();
            }

            var flightModel = await _context.Flight.FindAsync(id);
            if (flightModel == null)
            {
                return NotFound();
            }
            return View(flightModel);
        }


        [HttpPost]
        [ValidateAntiForgeryToken]
        public async Task<IActionResult> Edit(int id, FlightModel flightModel)
        {
            if (id != flightModel.Id)
            {
                return NotFound();
            }

            if (ModelState.IsValid)
            {
                try
                {
                    _context.Update(flightModel);
                    await _context.SaveChangesAsync();
                }
                catch (DbUpdateConcurrencyException)
                {
                    if (!FlightModelExists(flightModel.Id))
                    {
                        return NotFound();
                    }
                    else
                    {
                        throw;
                    }
                }
                return RedirectToAction(nameof(Index));
            }
            return View(flightModel);
        }

Answer 1

此代码_context.Update(flightModel); 将仅更新 flightModel，因此如果您还想更新 FlightClasses，您必须从 flightModel 获取 FlightClasses，然后对 FlightClasses 中的所有实例使用 _context.Update(flightClasse);。最后你使用await _context.SaveChangesAsync();