php - 在mysql上显示单个结果

Question

如何使用此代码仅获得 1 个结果？我试图计算我们可以在表中找到每个“ double ”的次数。数据库连接没有任何问题，它只得到重复的值作为结果。谢谢。

The output should be like

    DOUBLE       COUNT
    01 02          10 (as example)
    03 04          12 (as example)

    I am getting duplicated like...

    01 02          10 (as example)
    01 02          10 (as example)


<?php

if ($check == 'doubles'){

   sort($doubles);

   foreach ($doubles as $double) {

        explode(" ", $double);

        $dn1 = $double[0].$double[1];
        $dn2 = $double[2].$double[3];

if ($stmt = $post_con->prepare('SELECT DISTINCT FROM tb WHERE CONCAT(" ", res, " ") LIKE CONCAT("% ", ?, " %") AND CONCAT(" ", res, " ") LIKE CONCAT("% ", ?, " %")')) {

       $stmt->bind_param("ss", $dn1, $dn2);

       $dn1 = sprintf('%02d', $dn1);
       $dn2 = sprintf('%02d', $dn2);

       $stmt->execute();
       $stmt->store_result();
       $qty = $stmt->num_rows;

       echo '<div class="mini">'.$dn1.'</div>';
       echo '<div class="mini">'.$dn2.'</div>';
       echo '<div class="n-sort">'.$qty.'</div>';


        }


}
?>

Answer 1

很难准确匹配您的问题，因为我们不知道您的表结构(特别是 res 字段内容)，但我肯定认为这部分代码存在问题:

explode(" ", $double);

$dn1 = $double[0].$double[1];
$dn2 = $double[2].$double[3];

当$double采用01 02的值时，您将其分解为['01','02']，但是您不要捕获分解的数组。

然后，您使用的语法与分解数组和原始字符串都不兼容。连接后，您将得到以下结果:

$double = '01 02';
# index >  01234
$dn1 = '01';
$dn2 = ' 0';

按如下方式替换原来的代码:

$exploded = explode(" ", $double);
$dn1 = $exploded[0];
$dn2 = $exploded[1];

或者这样:

<s>explode(" ", $double);</s>
$dn1 = $double[0].$double[1];
$dn2 = $double[3].$double[4];