如何为 ASP.Net 身份用户 model 创建关系（一对一、多对多）

Question

I need create 2 relationships for Identity.User

1. One-to-One (i know, that is so bad, but i need this)

For example, to set additional user characteristics.

2. Many-to-Many

For example, for model of Books. User can have many books and a book can be with many users. Like in the library.

How I can do this. Thanks.

Answer 1

First of all. Many to Many Foreign Keys are not supported in SQL Server. The only way to achieve this (at least the only way I know) is to create a "mapping" table.

So you need three tables User, Books and UserBooks.

I will not dive into the details on how to do it but I will point you in the right direction.

Here is a Many To Many Tutorial on how to do this.

Here is Another Tutorial

The second one shows the table schema. This is pretty common.

I hope this helps you achieve your goal.

Answer 2

You can inherit from IdentityUser and pass your custom object that inherits from it in IdentityDbContext<> . Then your custom object can have additional members that you need including collection of books or singular properties.

Then you define the relationship when overriding OnModelCreating as specified here

As a rough example:

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity<CustomUser>()
        .HasOne(p => p.Name)
        .WithMany(b => b.Books);
}

Hope this helps.