Question

测试网站。以管理员身份登录时，用户应该能够删除服务。服务可以有子类别，称为＆＃34;服务选项＆＃34;以及＆＃34;服务选项项目＆＃34;。当管理员尝试永久删除服务时，他/她会收到以下服务器错误。

我做了一些研究，发现可能需要首先删除子类别，我相信代码反映了这一点。

控制器

 //
    // GET: /Service/Delete

    [Authorize(Roles = "admin")]
    public ActionResult Delete(int id)
    {
        Service serviceToDelete = db.Services.Where(s => s.ServiceId == id).Single();
        return View(serviceToDelete);
    }

    //
    // POST: /Service/Delete

    [HttpPost, ActionName("Delete")]
    public ActionResult DeleteConfirm(int id)
    {
        var serviceToDelete = db.Services.Where(s => s.ServiceId == id).Single();

        // remove the service option items
        var serviceOptionItems = db.ServiceOptionItems.Where(soi => soi.ServiceOption.ServiceId == serviceToDelete.ServiceId);
        foreach (var serviceOptionItem in serviceOptionItems)
        {
            db.ServiceOptionItems.Remove(serviceOptionItem);
        }

        // remove the service options
        var serviceOptions = db.ServiceOptions.Where(so => so.ServiceId == serviceToDelete.ServiceId);
        foreach (var serviceOption in serviceOptions)
        {
            db.ServiceOptions.Remove(serviceOption);
        }

        // remove the service
        db.Services.Remove(serviceToDelete);

        // save all changes
        db.SaveChanges();
        return RedirectToAction("Index", new { manage = "yes", mode = "all" });
    }

查看

@model YardLad.Models.Domain.Service

@{
ViewBag.Title = "Delete Service";
}

<script>
$(document).ready(function () {
    var isConfirmed = false;

    $("form").submit(function (e) {
        if (!isConfirmed)
        {
            $("#dialog-confirm").dialog({
                resizable: false,
                height: 140,
                modal: true,
                buttons: {
                    "Yes": function () {
                        $(this).dialog("close");
                        isConfirmed = true;
                        $("#deleteService").submit();
                    },
                    Cancel: function () {
                        $(this).dialog("close");
                    }
                }
            });

            e.preventDefault();
            return false;
        }
        else
        {
            return true;
        }
    });
});
 </script>

<h2>Delete</h2>

<h3>Are you sure you want to delete this service?</h3>

<div class="display-label">Service Category</div>
<div class="display-field">
@Html.DisplayFor(m => m.ServiceCategory.Name)
</div>

<div class="display-label">Name</div>
<div class="display-field">
@Html.DisplayFor(m => m.Name)
</div>

<div class="display-label">Description</div>
<div class="display-field">
@if (Model.Description == null)
{
    @:No Description
}
else
{
    @Html.DisplayFor(m => m.Description)
}

</div>

<div class="display-label">Base Price</div>
<div class="display-field">
@Html.DisplayFor(m => m.BasePrice)
</div>

<div class="display-label">Is Active</div>
<div class="display-field">
@Html.DisplayFor(m => m.IsActive)
</div>

@using (Html.BeginForm("Delete", "Service", null, FormMethod.Post, new { id = "deleteService" }))
{
<p>
    <input type="submit" id="btnSubmit" value="Delete" />
</p>
}

<div>
@Html.ActionLink("Back", "Index", new { manage = "yes" })
</div>


<div id="dialog-confirm" title="Delete this service?" class="hidden">
<p>This service will be permanently deleted and cannot be recovered. Are you     sure?</p>
</div>

模型

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Web;
using YardLad.Models.Domain;

namespace YardLad.Models.View
{
public class ServiceViewModel
{
    [Display(Name = "Service Id")]
    public int ServiceId { get; set; }

    [Required(ErrorMessage = "please enter a name")]
    public string Name { get; set; }

    [UIHint("multilinetext")]
    public string Description { get; set; }

    [Display(Name = "Base Price")]
    public decimal BasePrice { get; set; }

    [Display(Name = "Service Category")]
    [Required(ErrorMessage = "please select a category")]
    public int ServiceCategoryId { get; set; }

    [Display(Name = "Is Active?")]
    public bool IsActive { get; set; }

    [Display(Name = "Service options")]
    public List<ServiceOption> ServiceOptions { get; set; }
}

public class RequestServiceViewModel
{
    [Required(ErrorMessage = "please select a state")]
    public int StateId { get; set; }

    [Required(ErrorMessage = "please select a service area")]
    public int ServiceAreaId { get; set; }

    [Required(ErrorMessage = "please select a service")]
    public int ServiceId { get; set; }

    [Required(ErrorMessage = "please indicate the items selected")]
    public string[] SelectedServiceOptionItemIds { get; set; }

    [Required(ErrorMessage = "please indicate the contractors available for the request")]
    public string[] AvailableContractorIds { get; set; }

    public State SelectedState { get; set; }
    public ServiceArea SelectedServiceArea { get; set; }
    public Service SelectedService { get; set; }
    public List<ServiceOption> SelectedServiceOptions { get; set; }
    public List<ServiceOptionItem> SelectedServiceOptionItems { get; set; }
    public List<Contractor> AvailableContractors { get; set; }

    public int SelectedContractorId { get; set; }
    public Contractor SelectedContractor { get; set; }

    public int SelectedContractorServiceId { get; set; }
    public ContractorService SelectedContractorService { get; set; }

    public decimal SubTotal { get; set; }
    public decimal Tax { get; set; }
    public decimal SelectedContractorTaxRate { get; set; }
    public decimal Total { get; set; }

    public bool UserIsLoggedIn { get; set; }
    public int UserAddressId { get; set; }
    public Address UserAddress { get; set; }
    public bool CreateCustomAddress { get; set; }
    public Address CustomAddress { get; set; }
}

public class SelectContractorViewModel
{
    public int ServiceAreaId { get; set; }
    public ServiceArea SelectedServiceArea { get; set; }
    public int ServiceId { get; set; }
    public Service SelectedService { get; set; }
    public List<ServiceOption> ServiceOptions { get; set; }
    public List<ServiceOptionItem> ServiceOptionItems { get; set; }

    public List<Contractor> AvailableContractors { get; set; }

    public Contractor SelectedContractor { get; set; }
    public int ContractorTypeId { get; set; }
    public int ContractorServiceId { get; set; }
    public ContractorService SelectedContractorService { get; set; }
    public List<ContractorServiceOption> ContractorServiceOptions { get; set; }
    public List<ContractorServiceOptionItem> ContractorServiceOptionItems { get; set; }

    public decimal SubTotal { get; set; }
    public decimal Tax { get; set; }
    public decimal SelectedContractorTaxRate { get; set; }
    public decimal Total { get; set; }
}
}

数据库关系图： edmx

感谢您的阅读

Answer 1

您对表Service，ServiceOptions和ServiceOptions有外键约束。因此，您必须先删除该服务的所有ServiceOptionsItems和ServiceOptions，然后才能删除service。

但是如果你有这样的要求，我建议你在添加约束时使用ON DELETE CASCADE。因此，它允许您直接删除该服务，并会自动删除所有子ServiceOptions和ServiceOptionsItems。

更多信息：http://www.mysqltutorial.org/mysql-on-delete-cascade/

Answer 2

从错误消息中可以看出，Service与ContractorService之间存在关联。首先删除相关的ContactorService实体，或删除或更改其ServiceId值。

Answer 3

您的Service也与ContractorService相关，并且必须有一些子记录才会导致您发布的错误。您需要像删除其他表一样删除所有这些子项，但您还需要将子实体设置为Deleted：

[HttpPost, ActionName("Delete")]
public ActionResult DeleteConfirm(int id)
{
    var serviceToDelete = db.Services.Where(s => s.ServiceId == id).Single();

    // remove the service option items
    var serviceOptionItems = db.ServiceOptionItems.Where(soi => soi.ServiceOption.ServiceId == serviceToDelete.ServiceId);
    foreach (var serviceOptionItem in serviceOptionItems)
    {
        db.ServiceOptionItems.Remove(serviceOptionItem);
        db.Entry(serviceOptionItem).State = EntityState.Deleted;
    }

    // remove the service options
    var serviceOptions = db.ServiceOptions.Where(so => so.ServiceId == serviceToDelete.ServiceId);
    foreach (var serviceOption in serviceOptions)
    {
        db.ServiceOptions.Remove(serviceOption);
        db.Entry(serviceOption).State = EntityState.Deleted;
    }

    // remove the contractor services
    var contractorServices = db.ContractorServices.Where(so => so.ServiceId == serviceToDelete.ServiceId);
    foreach (var contractorService in contractorServices)
    {
        db.ContractorServices.Remove(contractorService);
        db.Entry(contractorService).State = EntityState.Deleted;
    }

    // remove the service
    db.Services.Remove(serviceToDelete);

    // save all changes
    db.SaveChanges();
    return RedirectToAction("Index", new { manage = "yes", mode = "all" });
}

MVC删除过程

3 个答案: