EF Core 2.0 Identity - Adding navigation properties

Question

In EF Core 2.0 Identity navigation properties are not included by default, so after upgrading, I added them. So for Many-To-Many relationship between User and Role, and One

Answer 1

I encountered with same issue and this is solution.

You have to tell Ef on which navigation property you are going to have OneToMany Relation.

protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);


        CreateUserModel(modelBuilder.Entity());
        CreateRoleModel(modelBuilder.Entity());

    }


    private void CreateRoleModel(EntityTypeBuilder entityTypeBuilder)
    {
        entityTypeBuilder.HasMany(role => role.UserRoles).
            WithOne(**e=> e.Role**).
            HasForeignKey(userRole => userRole.RoleId).
            IsRequired()
            .OnDelete(DeleteBehavior.Cascade);
    }

    private void CreateUserModel(EntityTypeBuilder entityTypeBuilder)
    {
        entityTypeBuilder.HasMany(user => user.UserRoles).
            WithOne(**e=>e.User**).
            HasForeignKey(userRole => userRole.UserId).
            IsRequired()
            .OnDelete(DeleteBehavior.Cascade);
    }

You can Also specify navigation property in string like

private void CreateRoleModel(EntityTypeBuilder entityTypeBuilder)
    {
        entityTypeBuilder.HasMany(role => role.UserRoles).
            WithOne(**"Role"**).
            HasForeignKey(userRole => userRole.RoleId).
            IsRequired()
            .OnDelete(DeleteBehavior.Cascade);
    }

    private void CreateUserModel(EntityTypeBuilder entityTypeBuilder)
    {
        entityTypeBuilder.HasMany(user => user.UserRoles).
            WithOne(**"User"**).
            HasForeignKey(userRole => userRole.UserId).
            IsRequired()
            .OnDelete(DeleteBehavior.Cascade);
    }