php - 使用 with() 从 Laravel 中的数据库中仅选择必填字段

Question

foreach(Book::with('author')->get() as $book)
{ 
   echo $book->author->name;
}

上面的循环就像下面的两个查询:

select * from books

select * from authors where id in (1, 2, 3, 4, 5, ...)

如果我想使用 laravel 5.6 只选择必填字段，如下面的查询，我该怎么做？

select book_name, book_description from books

select author_name from authors where id in (1, 2, 3, 4, 5, ...)

Answer 1

foreach(Book::with('author' => function($query){ $query->select('id', 'author_name'); })->select('book_name', 'book_description')->get() as $book)
{ 
   echo $book->author->name;
}