EF Core 6 Model Creation feedback

Question

Hi,

I am trying to design business models for my Blazor Server order management application. Here are my final conceptual models. I would like to hear your suggestions and tips. By the way, I am not sure about the User model. There might be users and roles for identity.

Order
-------
int OrderId
int OrderNumber - autoincrement from 1
DateTime OrderDate
string DoneBy
string Status
int CustomerId - navigation
OrderDetails - navigation
Customer - navigation

OrderDetail

----------

int OrderDetailId
int ProductNumber - autoincrement from 1
string ProductCode
string ProductName
int Quantity
double UnitPrice
double TotalPrice
string ShippingNumber
string Status
Description
int OrderId - navigation
int VendorId - navigation
Order - navigation
VendorId - navigation

Customer
--------
int CustomerId
string Name
string Address
string Email
string PhoneNumber
string MainResponsibleName
string AssistantResponsibleName

Vendor
-------
int VendorId
string Name
string Address
string Email
string PhoneNumber
string MainResponsibleName
string AssistantResponsibleName

User
-----
int UserId
string UserName
string Email

Should I also need to add relations to the model creation like the sample one below?

protected override void OnModelCreating(ModelBuilder modelBuilder)  
        {  
            //relations  
            modelBuilder.Entity<ProductInventory>()  
                .HasKey(pi => new { pi.ProductId, pi.InventoryId });  
  
            modelBuilder.Entity<ProductInventory>()  
                .HasOne(pi=>pi.Product)  
                .WithMany(p=>p.ProductInventories)  
                .HasForeignKey(pi => pi.ProductId);  
  
            modelBuilder.Entity<ProductInventory>()  
                .HasOne(pi => pi.Inventory)  
                .WithMany(p => p.ProductInventories)  
                .HasForeignKey(pi => pi.InventoryId);  

Answer 1

@Cenk , Welcome to Microsoft Q&A,

You could try the following code to generate autoincrement fields in ef core 6.

 protected override void OnModelCreating(ModelBuilder modelBuilder)  
        {  
            modelBuilder.Entity<Order>()  
    .Property(e => e.OrderNumber)  
    .ValueGeneratedOnAdd().UseIdentityColumn(1, 1);  
        }  

The above code means that OrderNumber column will start from 1 and increase by 1.

Hope this could help you.

Best Regards,
Jack

---

If the answer is the right solution, please click "Accept Answer" and upvote it.If you have extra questions about this answer, please click "Comment".

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Answer 2

OrderDetail in the Order should be List, right @Xinran Shen - MSFT ? Also how to generate autoincrement fields on EF Core 6? Let's say I want to make productNumber autoincrement. Should I add [DatabaseGenerated(DatabaseGeneratedOption.Identity)] data annotation to it? I want productNumber to start from 1.