c# - DELETE 语句冲突(ASP.NET MVC)

Question

我有 ASP.NET MVC 应用

我有两个相关表 Companies 和 Vacancies。

当我删除Company时，我想删除相对于它的Vacancies。

这是我的 Controller

  public ActionResult Delete(int? id)
    {
        if (id == null)
        {
            return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
        }
        Company companies = db.Companies.Find(id);
        if (companies == null)
        {
            return HttpNotFound();
        }
        return View(companies);
    }

    // POST: Companies/Delete/5
    [HttpPost, ActionName("Delete")]
    [ValidateAntiForgeryToken]
    public ActionResult DeleteConfirmed(int id)
    {
        Company companies = db.Companies.Find(id);
        db.Companies.Remove(companies);
        db.SaveChanges();
        return RedirectToAction("Index");
    }

这是公司表

CREATE TABLE [dbo].[Companies] (
[CompanyID]   INT            IDENTITY (1, 1) NOT NULL,
[CompanyName] NVARCHAR (MAX) NULL,
PRIMARY KEY CLUSTERED ([CompanyID] ASC)

);

职位空缺

CREATE TABLE [dbo].[Vacancies] (
[VacancyId]   INT        IDENTITY (1, 1) NOT NULL,
[VacancyName] NCHAR (10) NULL,
[CompanyID]   INT        NULL,
PRIMARY KEY CLUSTERED ([VacancyId] ASC),
CONSTRAINT [FK_Vacancies_ToTable] FOREIGN KEY ([CompanyID]) REFERENCES [dbo].[Companies] ([CompanyID])

);

我需要如何修改语法才能轻松删除公司？

Answer 1

修改你的依赖添加ON DELETE CASCADE

CREATE TABLE [dbo].[Vacancies] (
    [VacancyId]   INT        IDENTITY (1, 1) NOT NULL,
    [VacancyName] NCHAR (10) NULL,
    [CompanyID]   INT        NULL,
    PRIMARY KEY CLUSTERED ([VacancyId] ASC),
    CONSTRAINT [FK_Vacancies_ToTable] 
    FOREIGN KEY ([CompanyID]) 
    REFERENCES [dbo].[Companies] ([CompanyID])
    ON DELETE CASCADE);

这将允许在您删除公司时删除您的引用资料。或者，您可以将每个实体标记为已从 C# 中删除，这将为您提供更多控制并避免意外删除