Entity Framework - aktualizacja danych bez ich pobierania

log1.txt

2018-06-30 07:44:29.6430 INFO Opened connection at 30.06.2018 07:44:29 +02:00

2018-06-30 07:44:29.6669 INFO SELECT TOP (1) 
    [Extent1].[Id] AS [Id], 
    [Extent1].[Name] AS [Name], 
    [Extent1].[LockTime] AS [LockTime], 
    [Extent1].[Count] AS [Count]
    FROM [dbo].[Products] AS [Extent1]
    WHERE [Extent1].[Id] = @p__linq__0
2018-06-30 07:44:29.6669 INFO 

2018-06-30 07:44:29.6800 INFO -- p__linq__0: '2' (Type = Int32, IsNullable = false)

2018-06-30 07:44:29.6800 INFO -- Executing at 30.06.2018 07:44:29 +02:00

2018-06-30 07:44:29.7181 INFO -- Completed in 1 ms with result: SqlDataReader

2018-06-30 07:44:29.7181 INFO 

2018-06-30 07:44:29.7340 INFO Closed connection at 30.06.2018 07:44:29 +02:00

2018-06-30 07:44:29.7811 INFO Opened connection at 30.06.2018 07:44:29 +02:00

2018-06-30 07:44:29.7895 INFO Started transaction at 30.06.2018 07:44:29 +02:00

2018-06-30 07:44:29.8758 INFO UPDATE [dbo].[Products]
SET [LockTime] = @0
WHERE ([Id] = @1)

2018-06-30 07:44:29.8830 INFO -- @0: '30.06.2018 05:44:29' (Type = DateTime2)

2018-06-30 07:44:29.8830 INFO -- @1: '2' (Type = Int32)

2018-06-30 07:44:29.9011 INFO -- Executing at 30.06.2018 07:44:29 +02:00

2018-06-30 07:44:29.9198 INFO -- Completed in 11 ms with result: 1

2018-06-30 07:44:29.9198 INFO 

2018-06-30 07:44:29.9408 INFO Committed transaction at 30.06.2018 07:44:29 +02:00

2018-06-30 07:44:29.9490 INFO Closed connection at 30.06.2018 07:44:29 +02:00

log2.txt

2018-06-30 07:58:28.9270 INFO Opened connection at 30.06.2018 07:58:28 +02:00

2018-06-30 07:58:28.9345 INFO Started transaction at 30.06.2018 07:58:28 +02:00

2018-06-30 07:58:28.9345 INFO UPDATE [dbo].[Products]
SET [LockTime] = @0
WHERE ([Id] = @1)

2018-06-30 07:58:28.9485 INFO -- @0: '30.06.2018 05:58:28' (Type = DateTime2)

2018-06-30 07:58:28.9485 INFO -- @1: '2' (Type = Int32)

2018-06-30 07:58:28.9607 INFO -- Executing at 30.06.2018 07:58:28 +02:00

2018-06-30 07:58:28.9607 INFO -- Completed in 0 ms with result: 1

2018-06-30 07:58:28.9607 INFO 

2018-06-30 07:58:28.9876 INFO Committed transaction at 30.06.2018 07:58:28 +02:00

2018-06-30 07:58:28.9946 INFO Closed connection at 30.06.2018 07:58:28 +02:00

log3.txt

2018-06-30 08:11:06.8940 INFO Opened connection at 30.06.2018 08:11:06 +02:00

2018-06-30 08:11:06.8999 INFO Started transaction at 30.06.2018 08:11:06 +02:00

2018-06-30 08:11:06.8999 INFO UPDATE [dbo].[Products]
SET [LockTime] = @0, [Count] = @1
WHERE ([Id] = @2)

2018-06-30 08:11:06.9149 INFO -- @0: '30.06.2018 06:11:06' (Type = DateTime2)

2018-06-30 08:11:06.9149 INFO -- @1: '0' (Type = Int32)

2018-06-30 08:11:06.9310 INFO -- @2: '2' (Type = Int32)

2018-06-30 08:11:06.9310 INFO -- Executing at 30.06.2018 08:11:06 +02:00

2018-06-30 08:11:06.9469 INFO -- Completed in 2 ms with result: 1

2018-06-30 08:11:06.9469 INFO 

2018-06-30 08:11:06.9651 INFO Committed transaction at 30.06.2018 08:11:06 +02:00

2018-06-30 08:11:06.9651 INFO Closed connection at 30.06.2018 08:11:06 +02:00

log4.txt

2018-06-30 08:11:06.9930 INFO Opened connection at 30.06.2018 08:11:06 +02:00

2018-06-30 08:11:06.9930 INFO Started transaction at 30.06.2018 08:11:06 +02:00

2018-06-30 08:11:07.0100 INFO DELETE [dbo].[Products]
WHERE ([Id] = @0)
2018-06-30 08:11:07.0100 INFO 

2018-06-30 08:11:07.0100 INFO -- @0: '4' (Type = Int32)

2018-06-30 08:11:07.0260 INFO -- Executing at 30.06.2018 08:11:07 +02:00

2018-06-30 08:11:07.0260 INFO -- Completed in 1 ms with result: 1

2018-06-30 08:11:07.0391 INFO 

2018-06-30 08:11:07.0391 INFO Committed transaction at 30.06.2018 08:11:07 +02:00

Program1.cs

using (DataContext db = new DataContext())
{
    db.Database.Log = m => _logger.Info(m);

    var product = db.Products.FirstOrDefault(p => p.Id == productId);

    if (product == null)
    {
        return;
    }

    product.LockTime = DateTime.UtcNow;

    db.SaveChanges();
}

Program2.cs

using (DataContext db = new DataContext())
{
    db.Database.Log = m => _logger.Info(m);

    var product = new Product()
    {
        Id = productId
    };

    db.Set<Product>().Attach(product);

    product.LockTime = DateTime.UtcNow;
    product.Count = 0;

    db.SaveChanges();
}

Program3.cs

using (DataContext db = new DataContext())
{
    db.Database.Log = m => _logger.Info(m);

    var product = new Product()
    {
        Id = productId
    };

    db.Set<Product>().Attach(product);

    product.LockTime = DateTime.UtcNow;
    product.Count = 0;
    db.Entry(product).Property(p => p.Count).IsModified = true;

    db.SaveChanges();
}

Program4.cs

using (DataContext db = new DataContext())
{
    db.Database.Log = m => _logger.Info(m);

    var product = new Product()
    {
        Id = productId
    };

    db.Entry(product).State = EntityState.Deleted;

    db.SaveChanges();
}