更新1

正如@Florian指出的，我们不需要使用wp\\u list\\u pulk函数，只需添加\'fields\' => \'ids\' 到WP\\U查询以检索ID列表：

$producers = new WP_Query(
    array(
        \'fields\' => \'ids\',
        \'post_type\' => \'producers\',
        \'posts_per_page\' => -1,
        \'tax_query\' => array(
            array(
                \'taxonomy\' => \'region\',
                \'field\' => \'slug\',
                \'terms\' => \'alsace\'
            )
        )
    )
);

然后通过替换$producerIds来检索葡萄酒by$制片人->帖子`。

解决方案

首先，我必须从该地区取回生产商：

$producers = new WP_Query(
    array(
        \'post_type\' => \'producers\',
        \'posts_per_page\' => -1,
        \'tax_query\' => array(
            array(
                \'taxonomy\' => \'region\',
                \'field\' => \'slug\',
                \'terms\' => \'alsace\'
            )
        )
    )
);

然后使用wp_list_pluck:

$producerIds = wp_list_pluck($producers->posts, \'ID\');

最后，我用生产者的ID检索葡萄酒：

$wines = new WP_Query(
    array(
        \'post_type\' => \'wines\',
        \'posts_per_page\' => 12,
        \'tax_query\' => array(
            array(
                \'taxonomy\' => \'type\',
                \'field\' => \'slug\',
                \'terms\' => \'white\'
            )
        ),
        \'meta_query\' => array(
            array(
                \'key\' => \'producer\',
                \'value\' => $producerIds,
                \'compare\' => \'IN\'
            )
        )
    )
);