您可以使用SingleOrDefault获取与您的条件匹配的单个对象，然后将其传递给EF表的Remove方法。

var itemToRemove = Context.Employ.SingleOrDefault(x => x.id == 1); //returns a single item.

if (itemToRemove != null) {
    Context.Employ.Remove(itemToRemove);
    Context.SaveChanges();
}

Employer employer = context.Employers.First(x => x.EmployerId == 1);

context.Customers.DeleteObject(employer);
context.SaveChanges();

  var stud = (from s1 in entities.Students
            where s1.ID== student.ID
            select s1).SingleOrDefault();

  //Delete it from memory
  entities.DeleteObject(stud);
  //Save to database
  entities.SaveChanges();

不需要先查询对象，可以通过它的id将它附加到上下文。 是这样的:

var employer = new Employ { Id = 1 };
ctx.Employ.Attach(employer);
ctx.Employ.Remove(employer);
ctx.SaveChanges();

或者，你可以将附加条目的状态设置为已删除:

var employer = new Employ { Id = 1 };
ctx.Entry(employer).State = EntityState.Deleted;
ctx.SaveChanges();

我使用实体框架与LINQ。下面的代码对我很有帮助;

1-用于多条记录

 using (var dbContext = new Chat_ServerEntities())
 {
     var allRec= dbContext.myEntities;
     dbContext.myEntities.RemoveRange(allRec);
     dbContext.SaveChanges();
 }

2-单张唱片

 using (var dbContext = new Chat_ServerEntities())
 {
     var singleRec = dbContext.ChatUserConnections.FirstOrDefault( x => x.ID ==1);// object your want to delete
     dbContext.ChatUserConnections.Remove(singleRec);
     dbContext.SaveChanges();
 }

更普通的approuch

public virtual void Delete<T>(int id) where T : BaseEntity, new()
{
    T instance = Activator.CreateInstance<T>();
    instance.Id = id;
    if (dbContext.Entry<T>(entity).State == EntityState.Detached)
    {
        dbContext.Set<T>().Attach(entity);
    }

    dbContext.Set<T>().Remove(entity);
}

    [HttpPost]
    public JsonResult DeleteCotnact(int id)
    {
        using (MycasedbEntities dbde = new MycasedbEntities())
        {
            Contact rowcontact = (from c in dbde.Contact
                                     where c.Id == id
                                     select c).FirstOrDefault();

            dbde.Contact.Remove(rowcontact);
            dbde.SaveChanges();

            return Json(id);
        }
    }

你觉得这个简单与否，你也可以试试这个:

        var productrow = cnn.Product.Find(id);
        cnn.Product.Remove(productrow);
        cnn.SaveChanges();

对于泛型DAO，这是可行的:

    public void Delete(T entity)
    {
        db.Entry(entity).State = EntityState.Deleted;
        db.SaveChanges();
    }

使用EntityFramework。Plus可以是一个选项:

dbContext.Employ.Where(e => e.Id == 1).Delete();

这里有更多的例子

你可以像这样简单地做

   public ActionResult Delete(int? id)
    {
        using (var db = new RegistrationEntities())
        {
            Models.RegisterTable Obj = new Models.RegisterTable();
            Registration.DAL.RegisterDbTable personalDetail = db.RegisterDbTable.Find(id);
            if (personalDetail == null)
            {
                return HttpNotFound();
            }
            else
            {
                Obj.UserID = personalDetail.UserID;
                Obj.FirstName = personalDetail.FName;
                Obj.LastName = personalDetail.LName;
                Obj.City = personalDetail.City;

            }
            return View(Obj);
        }
    }


    [HttpPost, ActionName("Delete")]

    public ActionResult DeleteConfirmed(int? id)
    {
        using (var db = new RegistrationEntities())
        {
            Registration.DAL.RegisterDbTable personalDetail = db.RegisterDbTable.Find(id);
            db.RegisterDbTable.Remove(personalDetail);
            db.SaveChanges();
            return RedirectToAction("where u want it to redirect");
        }
    }

模型

 public class RegisterTable
{

    public int UserID
    { get; set; }


    public string FirstName
    { get; set; }


    public string LastName
    { get; set; }


    public string Password
    { get; set; }


    public string City
    { get; set; }

} 

从视图中调用它

 <table class="table">
    <tr>
        <th>
            FirstName
        </th>
        <th>
            LastName
        </th>

        <th>
            City
        </th>
        <th></th>
    </tr>

    @foreach (var item in Model)
    {
        <tr>
            <td> @item.FirstName </td>
            <td> @item.LastName </td>
            <td> @item.City</td>
            <td>
                <a href="@Url.Action("Edit", "Registeration", new { id = item.UserID })">Edit</a> |
                <a href="@Url.Action("Details", "Registeration", new { id = item.UserID })">Details</a> |
                <a href="@Url.Action("Delete", "Registeration", new { id = item.UserID })">Delete</a>

            </td>
        </tr>

    }

</table>

我希望这对你来说很容易理解

在实体框架6中，你可以使用Remove。 这也是一个很好的策略来确保你的连接是关闭的。

using (var context = new EmployDbContext())
{
    Employ emp = context.Employ.Where(x => x.Id == id).Single<Employ>();
    context.Employ.Remove(emp);
    context.SaveChanges();
}

你可以在网格的点击或celldoubleclick事件中这样做(如果你使用了一个)

if(dgEmp.CurrentRow.Index != -1)
 {
    employ.Id = (Int32)dgEmp.CurrentRow.Cells["Id"].Value;
    //Some other stuff here
 }

然后在删除按钮中执行如下操作:

using(Context context = new Context())
{
     var entry = context.Entry(employ);
     if(entry.State == EntityState.Detached)
     {
        //Attached it since the record is already being tracked
        context.Employee.Attach(employ);
     }                             
     //Use Remove method to remove it virtually from the memory               
     context.Employee.Remove(employ);
     //Finally, execute SaveChanges method to finalized the delete command 
     //to the actual table
     context.SaveChanges();

     //Some stuff here
}

或者，你可以使用LINQ查询，而不是使用LINQ到实体查询:

var query = (from emp in db.Employee
where emp.Id == employ.Id
select emp).Single();

雇佣。Id用作过滤参数，它已经从DataGridView的CellDoubleClick事件中传递。

这里有一个安全的方法:

using (var transitron = ctx.Database.BeginTransaction())
{
  try
  {
    var employer = new Employ { Id = 1 };
    ctx.Entry(employer).State = EntityState.Deleted;
    ctx.SaveChanges();
    transitron.Commit();
  }
  catch (Exception ex)
  {
    transitron.Rollback();
    //capture exception like: entity does not exist, Id property does not exist, etc...
  }
}

在这里，您可以堆积您想要的所有更改，因此您可以在SaveChanges和Commit之前执行一系列删除操作，因此只有当它们都成功时才会应用它们。

只是想贡献一下我反复使用的三个方法。

方法1:

var record = ctx.Records.FirstOrDefault();
ctx.Records.Remove(record);
ctx.SaveChanges();

方法2:

var record = ctx.Records.FirstOfDefault();
ctx.Entry(record).State = EntityState.Deleted;
ctx.SaveChanges();
ctx.Entry(record).State = EntityState.Detached;

我更喜欢使用方法2的原因之一是因为在设置EF或EFCore为QueryTrackingBehavior的情况下。NoTracking，这样做更安全。

还有方法3:

var record = ctx.Records.FirstOrDefault();
var entry = ctx.Entry(record);
record.DeletedOn = DateTimeOffset.Now;
entry.State = EntityState.Modified;
ctx.SaveChanges();
entry.State = EntityState.Detached;

通过设置记录的DeletedOn属性，这利用了一种软删除方法，并且仍然能够保留记录以供将来使用，无论将来可能使用什么。基本上就是把它放进回收站。

此外，对于方法3，不是将整个记录设置为要修改:

entry.State = EntityState.Modified;

你也可以简单地将DeletedOn列设置为modified:

entry.Property(x => x.DeletedOn).IsModified = true;

最好的办法是检查，然后删除

        if (ctx.Employ.Any(r=>r.Id == entity.Id))
        {
            Employ rec = new Employ() { Id = entity.Id };
            ctx.Entry(rec).State = EntityState.Deleted;
            ctx.SaveChanges();
        }