Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
629 views
in Technique[技术] by (71.8m points)

.net - best practise/way for master detail / multi table Insert in Entity Framework

My table structure is this

Orders
------ 
Id int identity
OrderDate smalldatetime
OrderStatusid tinyint

Products
--------
Id int identity
Name varchar(50)

OrderDetails
------------
Id int identity
OrderId int (fkey)
ProductId int (fkey)
Amount decimal
Rate decimal

I am trying to an insert operation using Entity Framework using the code below
Is this the best way to do the insert?
I am not happy with the way I am getting the full product item from the context object, instead of being able to just assign a simple productId value

using (MyContextEntities ctx = new MyContextEntities())
{
    Orders newOrder = new Orders()
    {
    Name = "Gayle Wynand",
    OrderDate = DateTime.Now,
    IsComplete = true,
    Comments = "test",
    OrderStatusId = 2,
    IsActive = true
    };
    OrderDetails ode = new OrderDetails();
    ode.Products = ctx.Products.First(p => p.Id == 2); // any other way?
    ode.Quantity = 2;
    ode.Rate = 5.2;
    newOrder.OrderDetails.Add(ode);

    OrderDetails ode2 = new OrderDetails();
    ode2.Products = ctx.Products.First(p => p.Id == 3); // any other way?
    ode2.Quantity = 3;
    ode2.Rate =6.5;
    newOrder.OrderDetails.Add(ode2);


    ctx.AddToOrders(newOrder);
    ctx.SaveChanges();
}

Is this the correct way to do the master detail insert or is there a better/another way.

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

What you are doing now will work just fine.

If you would like to avoid doing a database query when assigning ode.Products, then you could use the following alternative:

// substitute your actual qualified entity set name
ode.ProductsReference.EntityKey = 
    new EntityKey("MyEntities.ProductsEntitySetName", "Id", 2);

This is faster, but less readable. Also, the Products property will be null until you Load it. But for an insert, this is often OK.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

1.4m articles

1.4m replys

5 comments

57.0k users

...