Identity 3.0 - 如何在分层应用程序中使用 AspNetUsers ID 作为外键

Question

Intention:

A Subscriptions database table which contains a UserId column, which has a foreign key relationship to the Id column of the AspNetUsers table.

Project Setup (in order of their reference hierarchy) :

• Web Layer (Contains ApplicationDbContext and ApplicationUser class)
• DTO Layer
• Data Access Layer (Contains EFDbContext)

Project is Code-First configuration.

Database Setup:

Both ApplicationDbContext and EFDbContext reference the same database .

• ApplicationDbContext: References all Identity entities
• EFDbContext: References my Subscriptions entity (among others)

Question:

Given that my EFDbContext is located in my data layer, which does not contain any references to Identity 3.0 , is it possible to create a Foreign Key constraint between AspNetUsers and Subscriptions?

Answer 1

Is it possible to create a Foreign Key constraint between AspNetUsers and Subscriptions?

Sure it is. It's a common thing you will run into when you're crossing boundaries like that.

Instead of having EF create the relationships you need to

• create a new empty migration
• add the code to define the foreign key to the up method
• add the code to undo the foreign key in the down method
• run the migration on the database

The migration will look something like:

    protected override void Up(MigrationBuilder migrationBuilder)
    {
        migrationBuilder.AddForeignKey(
            name: "FK_Table_PrincipalTable_TableId",
            table: "Table",
            column: "PrincipalTableId",
            principalTable: "PrincipalTable",
            principalColumn: "Id",
            onDelete: ReferentialAction.Cascade)
    }

    protected override void Down(MigrationBuilder migrationBuilder)
    {
        migrationBuilder.DropForeignKey(
            name: "FK_Table_PrincipalTable_TableId",
            table: "Table");
    }