models

type Author struct {
	ID        uint   `gorm:"primary_key"`
	Firstname string `json:"FirstName"`
	Lastname  string `json:"LastName"`
}

type Book struct {
	Isbn     string `gorm:"primary_key" json:"ISBN"`
	Name     string `json:"name"`
	Author   Author `gorm:"foreignkey:AuthorID" json:",omitempty"`
	AuthorID uint   `json:"-"`
}