答案就在第一行SELECT post_title, ID, MIN( CAST(wm.meta_value AS UNSIGNED)) AS price - 你投到这里了UNSIGNED 它是整数，这是小数点的一部分。

所以解决方法就是更换UNSIGNED 具有DECIMAL(10,2) 或FLOAT

结果代码将以浮点数的方式显示

    $pts = $wpdb->get_results("SELECT post_title, ID, MIN( CAST(wm.meta_value AS FLOAT)) AS price FROM phiz_posts
            INNER JOIN phiz_postmeta wm ON (wm.post_id = phiz_posts.ID)
            INNER JOIN phiz_term_relationships wtr ON (phiz_posts.ID = wtr.object_id)
            INNER JOIN phiz_term_taxonomy wtt ON (wtr.term_taxonomy_id = wtt.term_taxonomy_id)
            INNER JOIN phiz_terms wt ON (wt.term_id = wtt.term_id) AND ((wtt.taxonomy = \'product_visibility\' AND  wt.slug = \'featured\'))
            INNER JOIN phiz_term_relationships rs ON rs.object_id = phiz_posts.ID    
            WHERE post_type = \'product\' 
            AND post_title = \'$title\'
            AND post_status = \'publish\' 
            AND rs.term_taxonomy_id = $product_cat_id
            AND (wm.meta_key = \'_regular_price\'
                  OR wm.meta_key = \'_sale_price\'
                  OR wm.meta_key = \'_price\')
            ORDER BY price");

    foreach($pts as $row)
    {
        $price = $row->price;
    }

或

    $pts = $wpdb->get_results("SELECT post_title, ID, MIN( CAST(wm.meta_value AS DECIMAL(10,2))) AS price FROM phiz_posts
            INNER JOIN phiz_postmeta wm ON (wm.post_id = phiz_posts.ID)
            INNER JOIN phiz_term_relationships wtr ON (phiz_posts.ID = wtr.object_id)
            INNER JOIN phiz_term_taxonomy wtt ON (wtr.term_taxonomy_id = wtt.term_taxonomy_id)
            INNER JOIN phiz_terms wt ON (wt.term_id = wtt.term_id) AND ((wtt.taxonomy = \'product_visibility\' AND  wt.slug = \'featured\'))
            INNER JOIN phiz_term_relationships rs ON rs.object_id = phiz_posts.ID    
            WHERE post_type = \'product\' 
            AND post_title = \'$title\'
            AND post_status = \'publish\' 
            AND rs.term_taxonomy_id = $product_cat_id
            AND (wm.meta_key = \'_regular_price\'
                  OR wm.meta_key = \'_sale_price\'
                  OR wm.meta_key = \'_price\')
            ORDER BY price");

    foreach($pts as $row)
    {
        $price = $row->price;
    }

对于十进制，总数字长度为10位，小数点后可以有2位，因此最好调整这些十进制参数，使其更适合您的数字范围。十进制在精度上胜过浮点数，但您需要注意可能的位数。