更新（与您的评论相关）
您可能正在尝试获取变量product id，而这与此不同。
然后您可以使用普通的产品属性分类法和术语名称值（甚至术语id或术语slug）。
在这种情况下，请尝试以下操作：

global $wpdb;

$results = $wpdb->get_col( "
    SELECT p.ID
    FROM {$wpdb->prefix}posts as p
    INNER JOIN {$wpdb->prefix}term_relationships as tr ON p.ID = tr.object_id
    INNER JOIN {$wpdb->prefix}term_taxonomy as tt ON tr.term_taxonomy_id = tt.term_taxonomy_id
    INNER JOIN {$wpdb->prefix}terms as t ON tt.term_id = t.term_id
    INNER JOIN {$wpdb->prefix}term_relationships as tr2 ON p.ID = tr2.object_id
    INNER JOIN {$wpdb->prefix}term_taxonomy as tt2 ON tr2.term_taxonomy_id = tt2.term_taxonomy_id
    INNER JOIN {$wpdb->prefix}terms as t2 ON tt2.term_id = t2.term_id
    WHERE p.post_type LIKE 'product'
    AND p.post_status LIKE 'publish'
    AND tt.taxonomy LIKE 'pa_color'
    AND t.name = 'Black'
    AND tt2.taxonomy LIKE 'pa_waterproof'
    AND t2.name = 'Yes'
");

// Raw output
echo '<pre>'; print_r($results); echo '</pre>';

测试和工作
第一个答案。
在商业中使用sql从特定的产品属性值获取产品变体id
在数据库中，产品属性在 post_meta 表是术语段塞（不是术语名）和所有产品属性 meta_key 从…开始 attribute_pa_ 而不是 pa_ .
就这样吧 attribute_pa_color = 'black' 以及 attribute_pa_waterproof = 'yes' 相反。
您还需要对 wp_posts 表 product_variation 柱型连接2倍 wp_postmeta 表来查询每个产品属性。
所以试试看：

global $wpdb;

$variation_id = $wpdb->get_var( "
    SELECT p.ID FROM {$wpdb->prefix}posts as p
    INNER JOIN {$wpdb->prefix}postmeta as pm ON p.ID = pm.post_id
    INNER JOIN {$wpdb->prefix}postmeta as pm2 ON p.ID = pm2.post_id
    WHERE p.post_type LIKE 'product_variation'
    AND p.post_status LIKE 'publish'
    AND pm.meta_key LIKE 'attribute_pa_color'
    AND pm.meta_value = 'black'
    AND pm2.meta_key LIKE 'attribute_pa_waterproof'
    AND pm2.meta_value = 'yes'
");

// Output
echo $variation_id . '<br>';

测试和工作