models

type Author struct {
	ID        int    `json:"id" gorm:"primary_key"`
	Firstname string `json:"firstname"`
	Lastname  string `json:"lastname"`
	BookID    int    `json:"bookID"`
}

type Book struct {
	ID       int    `json:"id" gorm:"primary_key"`
	Name     string `json:"name"`
	Category string `json:"category"`
	Author   []int  `json:"author" gorm:"polymorphic:Owner;"`
}