Php 从数组中删除唯一元素

因此，我一直在试图找到一种解决方案，从对象数组中删除唯一的元素并保留重复项，但几乎所有的问题都是关于如何删除重复项

该数组如下所示：

[{"No":"123","Product":"Name X","Color":"blue"},
 {"No":"123","Product":"Name X","Color":"green"},
 {"No":"456","Product":"Name X2","Color":"red"},
 {"No":"456","Product":"Name X2","Color":"blue"},
 {"No":"789","Product":"Name X3","Color":"yellow"}]

$db_result = array(); // Your array with duplicates

$count_occurrences = array();

foreach($db_result as $k=>&$v)
{
    $count_occurrences[$v['No']] = array(
        'key'=>$k,
        'count'=>(isset($count_occurrences[$v['No']]['count']) ? ($count_occurrences[$v['No']]['count'] + 1) : 1)
    );
}
unset($v);

foreach($count_occurrences as &$v)
{
    if($v['count'] === 1)
    {
        unset($db_result[$v['key']]);
    }
}
unset($v);

我需要检查

No

是否唯一，如果唯一，则将其删除。之后，阵列将如下所示：

[{"No":"123","Product":"Name X","Color":"blue"},
 {"No":"123","Product":"Name X","Color":"green"},
 {"No":"456","Product":"Name X2","Color":"red"},
 {"No":"456","Product":"Name X2","Color":"blue"}]

---

我试着从一开始就只获取重复的行（MySQL），但是所有的解决方案都使用了

groupby

和

HAVING

，它只返回重复的行，但也合并了它们。

所以你想删除只出现一次的数字。你可以在两次“通行证”中完成这项工作

首先，建立数字列表及其出现频率：

$numbers = array_reduce(
    $input,
    function($carry,$value) {
        if( !isset($carry[$value['No']])) $carry[$value['No']] = 0;
        $carry[$value['No']]++;
        return $carry;
    },
    []
);
$uniques = array_filter($numbers,function($n) {return $n == 1;});

现在您有了一个唯一编号的列表。所以你可以去掉那些匹配这些数字的

$result = array_filter(
    $input,
    function($item) use ($uniques) {
        return !isset($uniques[$item['No']]);
    }
);

---

完成。

我会选择这样的方式：

[{"No":"123","Product":"Name X","Color":"blue"},
 {"No":"123","Product":"Name X","Color":"green"},
 {"No":"456","Product":"Name X2","Color":"red"},
 {"No":"456","Product":"Name X2","Color":"blue"},
 {"No":"789","Product":"Name X3","Color":"yellow"}]

$db_result = array(); // Your array with duplicates

$count_occurrences = array();

foreach($db_result as $k=>&$v)
{
    $count_occurrences[$v['No']] = array(
        'key'=>$k,
        'count'=>(isset($count_occurrences[$v['No']]['count']) ? ($count_occurrences[$v['No']]['count'] + 1) : 1)
    );
}
unset($v);

foreach($count_occurrences as &$v)
{
    if($v['count'] === 1)
    {
        unset($db_result[$v['key']]);
    }
}
unset($v);

---

但是为什么同一个id有不同的颜色？欢迎来到StackOverflow！你说你已经尝试过一些事情了-你能发布你使用的代码吗？你也可以用sql查询来做到这一点：-

选择No，按c>1的产品分组计算（*）为c。检查引用：-您可以尝试先删除重复项，然后找到您获得的值，并在原始数组中删除它，以最终获得您想要的值，这只是一个想法。