php - 使用选择计数时隐藏 0

Question

下面是计数评论的脚本。这行得通，但现在我想当评论 0 时，它只显示评论，而不是 0 评论。

有什么建议么 ？

<?php
            include "con_config_hapshout.php";

            $query3 = "SELECT COUNT(comment) FROM comment WHERE msg_id='$id'";
            $result3 = mysql_query($query3);

            while($total = mysql_fetch_array($result3)){
                            echo "$total['COUNT(comment)'] comment";
                        }

            ?>

Answer 1

<?php
        include "con_config_hapshout.php";

        $query3 = "SELECT IF(COUNT(comment) = 0, '', COUNT(comment)) AS comment_count
                   FROM comment WHERE msg_id='$id'";
        $result3 = mysql_query($query3);

        while($total = mysql_fetch_array($result3)){
                        echo "$total['comment_count'] comment";
                    }

?>

Answer 2

按列名对结果进行分组。

SELECT COUNT(comment) 
FROM comment 
WHERE msg_id='$id'
GROUP BY comment

SQLFiddle 演示

Answer 3

您误用了 PHP 字符串 - 双引号字符串中的数组键引用不应被引用，除非您使用{}语法。

echo "{$total['COUNT(comment)']} comment";
      ^---                     ^--

或者更好的是，在查询中为计数设置别名，这样您以后就不必在 PHP 中使用如此丑陋的数组键：

SELECT COUNT(comment) AS cnt ...

and

echo $total['cnt'];