php - 如何将 foreach 与数组对象一起使用

Question

global $wpdb, $bp;
$result = $wpdb->get_results("SELECT user_id FROM wp_bp_xprofile_data WHERE value = '$_POST[language]' OR value = '$_POST[budget]' OR value = '$_POST[style]'LIMIT 0 , 30");
print_r($result);

输出是：

Array ( [0] => stdClass Object ( [user_id] => 2 )
        [1] => stdClass Object ( [user_id] => 2 ) 
        [2] => stdClass Object ( [user_id] => 2 ) 
        [3] => stdClass Object ( [user_id] => 4 ) )

我希望该值作为逗号分隔的字符串。

Answer 1

get_results()将返回一个对象。您可以简单地遍历对象并使用对象表示法访问 id，如下所示：

$arr = array();
foreach ($result as $k => $id) {
    $arr[] = $id->user_id;
}
$string = implode(',', $arr);

或者，您可以get_col()改用：

$result = $wpdb->get_col("SELECT user_id 
FROM wp_bp_xprofile_data 
WHERE value = '$_POST[language]' OR value = '$_POST[budget]' 
OR value = '$_POST[style]'LIMIT 0 , 300");

现在，要获取逗号分隔的字符串，请使用implode()：

$string = implode(',', $result);

Answer 2

当你必须得到一列时使用wpdb的 get_col

$result = $wpdb->get_col("SELECT user_id FROM wp_bp_xprofile_data WHERE value = '$_POST[language]' OR value = '$_POST[budget]' OR value = '$_POST[style]'LIMIT 0 , 30");

echo  implode(",",$result);
or 

echo  join(",",$result);

Answer 3

这是一个可能的解决方案；

<?php 
    global $wpdb, $bp;
    $result = $wpdb->get_results("SELECT user_id FROM wp_bp_xprofile_data WHERE 
                value = '$_POST[language]' OR value = '$_POST[budget]' 
                OR value = '$_POST[style]'LIMIT 0 , 30");
    $str_ids = '';
    foreach($result as $r) {
         $str_ids .= ('' == $str_ids) ? '' : ', ';
         $str_ids .= $r->user_id;
    }
    print_r($str_ids);

Answer 4

试试这个：

$str=implode(",",json_decode(json_encode($result),true));