Entity Framework 6 Where in Bulk Update/Delete in one transaction

问题

In EF6, I want to update/delete bulk data in one query. My code is

 using (var context = _dataContextFactory.GetContext())
            {
                var result1 = from b in context.MyTables
                    where new List<int> {592, 593, 594}.Contains(b.Id)
                    select b;


                foreach (var item in result1 )
                {
                    item.StatusId = 3;
                }

                context.SaveChanges();

            }

But in Sql Profiler, there are three scripts

exec sp_executesql N'UPDATE [dbo].[MyTable] SET [StatusId] = @0 WHERE ([Id] = @1) ',N'@0 int,@1 int',@0=1,@1=592
exec sp_executesql N'UPDATE [dbo].[MyTable] SET [StatusId] = @0 WHERE ([Id] = @1) ',N'@0 int,@1 int',@0=1,@1=593
exec sp_executesql N'UPDATE [dbo].[MyTable] SET [StatusId] = @0 WHERE ([Id] = @1) ',N'@0 int,@1 int',@0=1,@1=594

is it possible to get script with Where In clause in one query?

回答1:

Unfortunately, this is not supported in Entity Framework out of the box. However, you can use the batch update functionality in the EntityFramework.Extended library:

https://github.com/loresoft/EntityFramework.Extended

There's a nuget package available, too.

An example would be:

using EntityFramework.Extensions;

...

int[] myIds = { 592, 593, 594 };

using (var context = _dataContextFactory.GetContext())
{
    // Define a filter expression to retrieve matching items
    var filter = context.MyTables.Where(item => myIds.Contains(item.Id));
    // Update the StatusId of matched items
    context.MyTables.Update(filter, i => new Item { StatusId = 3 });

    // NB: no context.SaveChanges() required
}

NB: there may be a more efficient way of writing this, but I'm still playing with the library. It does compile down to a single SQL statement, however, and the library also includes batched DELETEs.

Finally, don't worry about the new expression. Any properties which are not referenced here will retain their original values.

回答2:

You can't update multiple rows in one single SQL call with EF.

What you could do instead is to write a stored procedure that'll do the job efficiently for you. Or use a third party lib that provides extensions to EF to do it.

Of course, it won't makes sense if the number of rows to update is really small.

来源：https://stackoverflow.com/questions/28584523/entity-framework-6-where-in-bulk-update-delete-in-one-transaction

标签

entity-framework-6