Question

我编写了以下代码来计算查询与一组属性之间的距离。但是，每个循环的产品属性返回相同，而实际上我知道它们不是。它可能与wpdb变量有关吗？

我已经尝试在循环顶部将变量重置为0，并且还尝试取消设置。当多个产品的距离值存在差异时，代码将正常工作。

请参阅以下代码：

      $the_query = get_posts( 'cat=2&post_type=product&fields=ids' );
    if($the_query){
        foreach($the_query as $id) {
                //reset variables at begining of foreach loop
                $distance = 0;
                $product_head_standard = 0;
                $product_loft = 0;
                $product_shape = 0;
                $product_trajectory_head_design = 0;
                //queries for product attributes
                $product_head_standard = $wpdb->query("SELECT meta_value FROM wp_postmeta 
WHERE meta_key = 'head_standard' AND post_id =".$id);
                $product_shape = $wpdb->query("SELECT meta_value FROM wp_postmeta 
WHERE meta_key = 'shape' AND post_id =".$id);
                $product_trajectory_head_design = $wpdb->query("SELECT meta_value 
FROM wp_postmeta WHERE meta_key = 'trajectory_head_design' AND post_id =".$id);
                $product_loft = $wpdb->query("SELECT meta_value FROM wp_postmeta 
WHERE meta_key = 'loft' AND post_id =".$id);
                echo $product_head_standard."productheadstandard";
                echo $product_loft."productloft";
                echo $product_shape."shape";
                echo $product_trajectory_head_design."producttracjectory";
                //calculate total height
                $height_variables = $product_trajectory_head_design + $product_loft;
                //calculate difference between search query and product attributes
                $distance = ABS($form_standard-$product_head_standard)
 + ABS($form_desired_shape-$product_shape) + ABS($form_desired_height-$height_variables);
                //output
                echo "<tr><p>id".$id."      distance".$distance."</p></tr>";

Answer 1

我认为必须使用get_var选择单个值，如此

$value = $wpdb->get_var("sql goes here");

我相信你得到的数字不是你想要的价值。也许是结果的数量。

在FOREACH循环期间变量不重置

1 个答案: