028 Modify DBContext for the entity with foreign key (Division) - chempkovsky/CS82ANGULAR GitHub Wiki

• Run DBContext Wizard
• First page of DBContext Wizard
• Second page of DBContext Wizard
• Sixth page of DBContext Wizard
• Primary Key page of DBContext Wizard
• Unique Key page of DBContext Wizard
• Second page of DBContext Wizard second time
• Foreign Keys page of DBContext Wizard
• Create or Modify Foreign Keys page of DBContext Wizard

• read the following article as reminder

• repeat the steps described in the article

• repeat the steps described in the article

• repeat the steps described in the article

On the Sixth page of the Wizard choose PhBkEntity.csproj and PhbkEnterprise-class and click Add Required property to Db-context-button

It will add the following lines of code to the PhbkDbContext.cs file.

        public DbSet<PhbkDivision> PhbkDivisionDbSet {
            get => Set<PhbkDivision>();
            
        }

In addition the content of the second page of the Wizard has changed. Now it shows the message about the primary Key of the entity. Click Modify-button. (It will show Primary Key page of DBContext Wizard.)

• On the Primary Key page
  • choose DivisionId-property to be used as a primary key,
  • choose HasKey.Net.Core.cs.t4-script to generate the code
  • click Create(modify)-button

It modifies OnModelCreating-method of the DbContext class as shown below:

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
             ...
             modelBuilder.Entity<PhbkDivision>().HasKey(p => p.DivisionId);
             ...
        }

Click Next-button to navigate to Unique Key page of DBContext Wizard

We do not require additional unique keys for the PhbkDivision-entity, so click Next-button on this page. It will navigate to the second page of the wizard.

• To modify Foreign Key Setting click Next-button

• The Wizard shown only one foreign key which is not completely defined
  • click first row in the panel
  • click Next button

• On this page of the Wizard
  • select EntrprsIdRef-property of the PhbkDivision-entity
  • select One-to-Many-type of the foreign key
  • select OneToCollection.Net.Core.cs.t4-script
  • click Create(Modify)-button

It will modify OnModelCreating-method

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            ...
            modelBuilder.Entity<PhbkDivision>().HasOne(d => d.Enterprise)
                .WithMany(m => m.Divisions)
                .HasForeignKey(d => d.EntrprsIdRef)
                .HasPrincipalKey(p => p.EntrprsId)
                .IsRequired(true)
                .OnDelete(DeleteBehavior.NoAction);
            ...
        }

• click Next-button
  • you will be back on the third page
    • click Next-button
      • it shows Foreign Keys-page of the Wizard

• close the Wizard