How to get data from another table and insert into the required table in EF core-CodePudding

This is a webapi project in .NET 5 and EF Core version 5.0.9. I am testing this API using Swagger. And the database is SQLite.
I have 3 tables Product, StockHeader and StockDetail. StockHeader and StockDetail are in one-to-many relationship.
Product table has these columns->

Id
Name
Rate

StockHeader table has these columns->

HdrId
DocumentNo
Sign
ICollection of the type StockDetail

StockDetail table has these columns->

Id
HdrId(Foreign key)
ProductId
Rate

So, my requirement is that when I enter the value of productID in stockDetail,it should look upto the Product table, take the rate of that particular Id and write it in my StockDetails' Rate column.
I have to do this in HttpPost.
The problem is that StockDetail should not have any reference property of Product. How can I achieve this in EF Core?

CodePudding user response：

Add a simply product property in your stockdetail class and one ienumerable in product class... And add with fluent api a row in your contex, that map productId with your object product...

modelBuilder.Entity<Product>()
            .HasMany<StockDetail>(s => s.stockDetaik)
            .WithOne(ad => ad.Product)
            .HasForeignKey<Product>(ad => ad.ProductId);

CodePudding user response：

Okay so I guess you will have the productId as an input parameter. You just have to make a LINQ query to get the desired product form the Products DbSet.

Try with:

var product = dbContext.Products.FirstOrDefault(x => x.Id == productId);

It is good to check if the input parameter (productId) was a valid Id so you can write this:

if(product == null)
    throw new ArgumentException("Invalid ID", nameof(productId));

and after that just assign the Rate so that:

Rate = product.Rate;