Delete a single record from Entity Framework?
C#Sql ServerEntity FrameworkC# Problem Overview
I have a SQL Server table in Entity Framework named employ with a single key column named ID.
How do I delete a single record from the table using Entity Framework?
C# Solutions
Solution 1 - C#
It's not necessary to query the object first, you can attach it to the context by its id. Like this:
var employer = new Employ { Id = 1 };
ctx.Employ.Attach(employer);
ctx.Employ.Remove(employer);
ctx.SaveChanges();
Alternatively, you can set the attached entry's state to deleted :
var employer = new Employ { Id = 1 };
ctx.Entry(employer).State = EntityState.Deleted;
ctx.SaveChanges();
Solution 2 - C#
You can use SingleOrDefault to get a single object matching your criteria, and then pass that to the Remove method of your EF table.
var itemToRemove = Context.Employ.SingleOrDefault(x => x.id == 1); //returns a single item.
if (itemToRemove != null) {
Context.Employ.Remove(itemToRemove);
Context.SaveChanges();
}
Solution 3 - C#
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();
Solution 4 - C#
Employer employer = context.Employers.First(x => x.EmployerId == 1);
context.Customers.DeleteObject(employer);
context.SaveChanges();
Solution 5 - C#
I am using entity framework with LINQ. Following code was helpful for me;
1- For multiple records
using (var dbContext = new Chat_ServerEntities())
{
var allRec= dbContext.myEntities;
dbContext.myEntities.RemoveRange(allRec);
dbContext.SaveChanges();
}
2- For Single record
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();
}
Solution 6 - C#
More generic 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);
}
Solution 7 - C#
With Entity Framework 6, you can use Remove.
Also it 's a good tactic to use using for being sure that your connection is closed.
using (var context = new EmployDbContext())
{
Employ emp = context.Employ.Where(x => x.Id == id).Single<Employ>();
context.Employ.Remove(emp);
context.SaveChanges();
}
Solution 8 - C#
Just wanted to contribute the three methods I've bounced back and forth with.
Method 1:
var record = ctx.Records.FirstOrDefault();
ctx.Records.Remove(record);
ctx.SaveChanges();
Method 2:
var record = ctx.Records.FirstOfDefault();
ctx.Entry(record).State = EntityState.Deleted;
ctx.SaveChanges();
ctx.Entry(record).State = EntityState.Detached;
One of the reasons why I prefer to go with Method 2 is because in the case of setting EF or EFCore to QueryTrackingBehavior.NoTracking, it's safer to do.
Then there's Method 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;
This utilizes a soft delete approach by setting the record's DeletedOn property, and still being able to keep the record for future use, what ever that may be. Basically, putting it in the Recycle Bin.
Also, in regards to Method 3, instead of setting the entire record to being modified:
entry.State = EntityState.Modified;
You would also simply set only the column DeletedOn as modified:
entry.Property(x => x.DeletedOn).IsModified = true;
Solution 9 - C#
[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);
}
}
What do you think of this, simple or not, you could also try this:
var productrow = cnn.Product.Find(id);
cnn.Product.Remove(productrow);
cnn.SaveChanges();
Solution 10 - C#
For a generic DAO this worked:
public void Delete(T entity)
{
db.Entry(entity).State = EntityState.Deleted;
db.SaveChanges();
}
Solution 11 - C#
Using EntityFramework.Plus could be an option:
dbContext.Employ.Where(e => e.Id == 1).Delete();
More examples are available here
Solution 12 - C#
u can do it simply like this
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");
}
}
model
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; }
}
view from which u will call it
<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>
i hope this will be easy for u to understand
Solution 13 - C#
You can do something like this in your click or celldoubleclick event of your grid(if you used one)
if(dgEmp.CurrentRow.Index != -1)
{
employ.Id = (Int32)dgEmp.CurrentRow.Cells["Id"].Value;
//Some other stuff here
}
Then do something like this in your Delete Button:
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
}
Alternatively, you can use a LINQ Query instead of using LINQ To Entities Query:
var query = (from emp in db.Employee
where emp.Id == employ.Id
select emp).Single();
employ.Id is used as filtering parameter which was already passed from the CellDoubleClick Event of your DataGridView.
Solution 14 - C#
Here's a safe way:
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...
}
}
Here you can pile up all the changes you want, so you can do a series of deletion before the SaveChanges and Commit, so they will be applied only if they are all successful.
Solution 15 - C#
The best way is to check and then delete
if (ctx.Employ.Any(r=>r.Id == entity.Id))
{
Employ rec = new Employ() { Id = entity.Id };
ctx.Entry(rec).State = EntityState.Deleted;
ctx.SaveChanges();
}