Php 从wordpress的两个表中获取列行的总和

我需要从wordpress Posteta表中获取列中特定行的总数。这就像php、mysql查询求和一样。但我返回的是一个空数组

这是我的密码： 我正在

WP\u query

中运行此查询，因此

get\u title（）

将自动从

WP\u query

中检索。我实际上想平均

查看\u评级

元键值的评级

 $results = $wpdb->get_results( 
                        $wpdb->prepare("query", $some_parameter) 
                     );

试一试

试试这个

global $wpdb;
$title = get_the_title();
$avg_ratings = 
"
SELECT sum($wpdb->postmeta.meta_value) 
AS TotalRating
FROM $wpdb->posts, $wpdb->postmeta
WHERE $wpdb->posts.ID = $wpdb->postmeta.post_id 
AND $wpdb->postmeta.meta_key = 'review_rating'  
AND $wpdb->posts.post_title = '$title'
AND $wpdb->posts.post_status = 'publish' 
AND $wpdb->posts.post_type = 'reviews'
";
$avg_rating = $wpdb->get_results( $avg_ratings, OBJECT );

print_r($avg_rating);

试试这个

global $wpdb;
$title = get_the_title();
$avg_ratings = 
"
SELECT sum($wpdb->postmeta.meta_value) 
AS TotalRating
FROM $wpdb->posts, $wpdb->postmeta
WHERE $wpdb->posts.ID = $wpdb->postmeta.post_id 
AND $wpdb->postmeta.meta_key = 'review_rating'  
AND $wpdb->posts.post_title = '$title'
AND $wpdb->posts.post_status = 'publish' 
AND $wpdb->posts.post_type = 'reviews'
";
$avg_rating = $wpdb->get_results( $avg_ratings, OBJECT );

print_r($avg_rating);