Php 将两个字段连接为valueField

我正在尝试将两个联接字段合并为下拉组合中的valueField。 检查后，我尝试了以下方法：

这是有效的：

$authorities = $this->Books->Authorities->find('list', [
            'valueField' => 'author.name'])
            ->contain(['Authors', 'AuthorTypes']);

$authorities = $this->Books->Authorities->find('list', [
            'valueField' => 'author_type.name'])
            ->contain(['Authors', 'AuthorTypes']);

$authorities = $this->Books->Authorities->find('list', [
            'valueField' => function ($row) {
                return $row['author.name'] . ' - ' . $row['author_type.name'];
            }])
        ->contain(['Authors', 'AuthorTypes']);

这也有效：

$authorities = $this->Books->Authorities->find('list', [
            'valueField' => 'author.name'])
            ->contain(['Authors', 'AuthorTypes']);

$authorities = $this->Books->Authorities->find('list', [
            'valueField' => 'author_type.name'])
            ->contain(['Authors', 'AuthorTypes']);

$authorities = $this->Books->Authorities->find('list', [
            'valueField' => function ($row) {
                return $row['author.name'] . ' - ' . $row['author_type.name'];
            }])
        ->contain(['Authors', 'AuthorTypes']);

但这不是：

$authorities = $this->Books->Authorities->find('list', [
            'valueField' => 'author.name'])
            ->contain(['Authors', 'AuthorTypes']);

$authorities = $this->Books->Authorities->find('list', [
            'valueField' => 'author_type.name'])
            ->contain(['Authors', 'AuthorTypes']);

$authorities = $this->Books->Authorities->find('list', [
            'valueField' => function ($row) {
                return $row['author.name'] . ' - ' . $row['author_type.name'];
            }])
        ->contain(['Authors', 'AuthorTypes']);

---

我不明白为什么。有什么想法吗？：）

作为建议的评论之一，请遵循以下内容

您的代码应该是：

$authorities = $this->Books->Authorities->find('list', [
            'valueField' => function ($row) {
                return $row->author->name . ' - ' . $row->author->name;
            }])
            ->contain(['Authors', 'AuthorTypes']);

---

这称为

自定义键值输出

。$row参数是一个对象，而不是一个简单的数组对象。

下面的示例应该是

$row->author->name

我必须是盲的…因为即使现在我也看不到它是同一个示例^\u^！