在多个项目中共享数据库，采用代码优先方法

Question

I have two project inside vs solution

Product.Domain and Product.Web.UI

On both project I want to use code first approach and be able to work with data (domain and ui project).

So I created inside domain project simple class which implements DbContext I have two projects, Product.Domain and Product.UI

I'm using entity framework code first approach. Inside MasterProject I have class which represents db table Products

public class ProductsDbContext : DbContext{
      public ProductsDbContext() : base("name=ProductsDbContext") { }
 }

in my app.config I have connection string ProductsDbContext which handled connection to db.

Now I want to use ApplicationDbContext inside UI project which should use same database from domain layer and store identity tables (which initially does not exist in database when domain layer was created db) I tried to set ProductsDbContext in web.config connection string and to use in ApplicationDbContext constructor like

public class ApplicationDbContext : IdentityDbContext<ApplicationUser>
{
    public ApplicationDbContext()
         : base("name=ProductsDbContext") { }
    public static ApplicationDbContext Create()
    {
        return new ApplicationDbContext();
    }       
}

How should I continue in Configuration.cs Seed() to use ApplicationDbContext in order to store sample user and sample Product in same database defined in ProductsDbContext.

I'm looking more describe to this solution, when database is created initially in one project (domain) than used again in different project and possibly updated with new tables (ui). Is this proper approach? Any example to share?

Answer 1

If you want 2 DbContexts in 2 separate projects they will always be disjointed.

Eg You will not be able to do something like the following:

Context1.Users.Where(u => Context2.Products.Any(p => p.User == u))

So you will loose the ability to use joins across both databases.

One way to seed your data is to use conde first migrations pointing them at both projects, eg

• Enable-Migrations on Master Project
• Enable-Migrations on Web.UI Project

In visual studio, in the Package Manager Console, you have an option to choose which project you want to target.

Then you can add migrations and seed data in the respective projects Configuration.cs .