Ndtyjky

A product can have multiple reviews. A review is made by a single customer.
Therefore, review has both Customer and Product as properties.

Product.cs

namespace DatabaseProject.Models

{

    public class Product

    {

        public Product()

        {

            Reviews = new List < Review >();

        }



        public int Id { get; set; }

        public Catagory Catagory { get; set; }

        public string Name { get; set; }

        public string Description { get; set; }

        public string Specification { get; set; }

        public List<Review> Reviews { get; set; }

    }

}

Review.cs

namespace DatabaseProject.Models

{

    public class Review

    {

        public int Id { get; set; }

        public string Text { get; set; }

        public int Stars { get; set; }

        [Required]

        public Product Product { get; set; }

        [Required]

        public Customer Customer { get; set; }

    }

}

Customer.cs

namespace DatabaseProject.Models

{

    public class Customer

    {

        public Customer()

        {

            Addresses = new List<Address>();

            Reviews = new List<Review>();

        }



        public int Id { get; set; }

        public string FirstName { get; set; }

        public string LastName { get; set; }

        public string Email { get; set; }

        public string Password { get; set; }

        public List<Address> Addresses { get; set; }

        public List<Review> Reviews { get; set; }

    }

}

Method to add new review.

I add it to the reviews list in product table.

public bool AddReview(int id, Review review)

{

    using (var context = new ShopDbContext())

    {

        Product oldProduct = context.Products.Find(id);

        if (oldProduct == null)

        {

            return false;

        }

        oldProduct.Reviews.Add(review);





            context.SaveChanges();

            return true;

        }

    }

Adding a new Review

Here, since the review is added to product.Reviews I didn't have to pass the product property.

But I had to pass the customer. Somehow this creates a new customer rather than referencing the existing customer.

    productService.AddReview(1,

        new Review

        {

            Customer = customerService.Get(1),

            Stars = 2,

            Text = "It's a good camera",

        });

This causes a duplicate entry in Customers table.

I think you need a CustomerId propery in your Reviews table, and pass the customerId when adding a new review.

public class Review

{

    public int Id { get; set; }

    public string Text { get; set; }

    public int Stars { get; set; }

    [Required]

    public int ProductId { get; set; }

    [Required]

    public int CustomerId { get; set; }

    [ForeignKey("ProductId")]

    public Product Product { get; set; }

    [ForeignKey("CustomerId")]

    public Customer Customer { get; set; }

}



productService.AddReview(1,

    new Review

    {

        CustomerId = 1,

        ProductId = XXX,

        Stars = 2,

        Text = "It's a good camera",

    })

Then, you would need to create a foreign key between ProductId and Product table, and CustomerId and Customer table.

In this way, you wouldn't need to load the customer/product when addign a new review. You will only need the identifiers.

Your Review Model should have a CustomerID & Review Model should look like this:

namespace DatabaseProject.Models

{

    public class Review

    {

        public int Id { get; set; }

        [Required]

        public int CustomerId { get; set; }

        [Required]

        public int ProductId { get; set; }

        public string Text { get; set; }

        public int Stars { get; set; }



        [ForeignKey("ProductId")]

        public Product Product { get; set; }



        [ForeignKey("CustomerId")]

        public Customer Customer { get; set; }

    }

}

And you must add a new review like this:

productService.AddReview(1,

    new Review

    {

        CustomerId = 1,

        Stars = 2,

        Text = "It's a good camera",

        ProductId = 1

    })

In present code you are passing an object of Customer Model in DbSet.Add method which adds a new entity to a context