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c#sqlentity-frameworkt-sql
Elad Benda
Elad Benda

Reputation: 36654

How to perform delete rows on some condition with EF?

in ADO.NET I can use delete statement

to delete some rows from an SQL table.

what is the equivalent in Entity Framework?

How can I achieve that same result?

updateing with null objects isn't the same.

Upvotes: 4

Views: 14101

Answers (3)

Saman Gholami
Saman Gholami

Reputation: 3512

First of all you need to create instance from your Database entities,after that you should select your desired object,then delete it : 

TestEntities db = new TestEntities();
Test ts = (from rows in db.Tests
           where rows.ID == 1
           select rows).FirstOrDefault();
if (ts != null)
{
     db.Tests.DeleteObject(ts);
     db.SaveChanges();
}

Update :

If your result set is a list, I mean more than one record you can use this solution : 

List<Test> lst = (from rows in db.Tests select rows).ToList();
foreach (Test item in lst)
{ 
     db.Tests.DeleteObject(item);
}
db.SaveChanges();

Upvotes: 0

cincura.net
cincura.net

Reputation: 4150

Replies telling you, that you need to first fetch objects (strictly speaking keys are enough, but then you need to do some work manually) into memory and mark them for deletion and finally call SaveChanges. Though that's the "normal" approach, there's bunch of extensions, helpers, ... that allow you to do i.e. batch deletes, batch updates and other helpful stuff.

You can check EntityFramework.Extended (also on GitHub) or Entity Framework Extensions (sources there as well).

Upvotes: 3

Iswanto San
Iswanto San

Reputation: 18569

You need to retrieve the object to be deleted first. For example : 

 // Assuming ID is primary key in `Customer` entity
 Customer cust = (from c in context.Customers where c.ID = "1" select c);

Then delete the object using DataContext.entity.DeleteObject 

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

More : DataContext

Upvotes: 2

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