AuthorBooks\Model\BookSchema::schema PHP Method

    public function schema()
    {
        $this->column('title')->unique()->varchar(128);
        $this->index('idx_book_title_subtitle', ['title', 'subtitle']);
        $this->column('subtitle')->varchar(256);
        $this->column('isbn')->varchar(128)->immutable()->findable();
        $this->column('description')->text();
        $this->column('view')->default(0)->integer();
        $this->column('publisher_id')->integer()->unsigned();
        $this->column('published_at')->isa('DateTime')->timestamp()->default(function () {
            return new \DateTime();
        });
        // Create a flag column named "is_hot" labeld "Hot Sale", checked by default
        $this->helper('Flag', ['is_hot', 'Hot Sale', true]);
        $this->helper('Flag', ['is_selled', 'Selled', false]);
        /** 
         * Column: author => Author class 
         *
         * $book->publisher->name;
         **/
        $this->belongsTo('publisher', 'AuthorBooks\\Model\\PublisherSchema', 'id', 'publisher_id');
        /**
         * accessor , mapping self.id => BookAuthors.book_id
         *
         * link book => author_books
         */
        $this->many('book_authors', 'AuthorBooks\\Model\\AuthorBookSchema', 'book_id', 'id');
        $this->addModelTrait('TestApp\\ModelTrait\\EBookTrait');
        $this->addModelInterface('TestApp\\ModelInterface\\EBookInterface');
        $this->addCollectionTrait('TestApp\\ModelTrait\\EBookCollectionTrait');
        $this->addCollectionInterface('TestApp\\ModelInterface\\EBookCollectionInterface');
        /**
         * get BookAuthor.author 
         */
        $this->manyToMany('authors', 'book_authors', 'author')->filter(function ($collection) {
            return $collection;
        });
    }