PHP mysql选择数组并检查值是否存在

我有一张MySQL表：

我想从中获得每个平台的计数（windows、linux、mac、未知）

注意，在表中没有

mac

或

unknown

数据，num将有

0

条件：

• 订单必须与所需的输出相同
• 检查plaform是否在表中，如果不在，则将零添加到输出中

问题：如何在查询中排序，使其具有与所需输出类似的顺序，如果表中没有平台，则添加零

想要的输出：

array (
    '0' => array('name' => 'windows', 'num' => 3),
    '1' => array('name' => 'linux', 'num' => 3),
    '2' => array('name' => 'mac', 'num' => 0),
    '3' => array('name' => 'unknown', 'num' => 0)
);

function get_platforms() {
    $query = "
            SELECT platform, COUNT(platform) AS num 
            FROM stats 
            GROUP BY platform 
            ORDER BY platform ASC
            ";
    $select = mysqli_query($this->c, $query);
    while ($row = mysqli_fetch_array($select)) {
        $data[] = array(
            'name' => $row['platform'],
            'num' => $row['num']
        );
    }
    return $data;
}

array (
    '0' => array ('name' => 'linux', 'num' => 3)
    '1' => array ('name' => 'windows', 'num' => 3)
);

我的尝试：

array (
    '0' => array('name' => 'windows', 'num' => 3),
    '1' => array('name' => 'linux', 'num' => 3),
    '2' => array('name' => 'mac', 'num' => 0),
    '3' => array('name' => 'unknown', 'num' => 0)
);

function get_platforms() {
    $query = "
            SELECT platform, COUNT(platform) AS num 
            FROM stats 
            GROUP BY platform 
            ORDER BY platform ASC
            ";
    $select = mysqli_query($this->c, $query);
    while ($row = mysqli_fetch_array($select)) {
        $data[] = array(
            'name' => $row['platform'],
            'num' => $row['num']
        );
    }
    return $data;
}

array (
    '0' => array ('name' => 'linux', 'num' => 3)
    '1' => array ('name' => 'windows', 'num' => 3)
);

PHP:

array (
    '0' => array('name' => 'windows', 'num' => 3),
    '1' => array('name' => 'linux', 'num' => 3),
    '2' => array('name' => 'mac', 'num' => 0),
    '3' => array('name' => 'unknown', 'num' => 0)
);

function get_platforms() {
    $query = "
            SELECT platform, COUNT(platform) AS num 
            FROM stats 
            GROUP BY platform 
            ORDER BY platform ASC
            ";
    $select = mysqli_query($this->c, $query);
    while ($row = mysqli_fetch_array($select)) {
        $data[] = array(
            'name' => $row['platform'],
            'num' => $row['num']
        );
    }
    return $data;
}

array (
    '0' => array ('name' => 'linux', 'num' => 3)
    '1' => array ('name' => 'windows', 'num' => 3)
);

当前输出：

array (
    '0' => array('name' => 'windows', 'num' => 3),
    '1' => array('name' => 'linux', 'num' => 3),
    '2' => array('name' => 'mac', 'num' => 0),
    '3' => array('name' => 'unknown', 'num' => 0)
);

function get_platforms() {
    $query = "
            SELECT platform, COUNT(platform) AS num 
            FROM stats 
            GROUP BY platform 
            ORDER BY platform ASC
            ";
    $select = mysqli_query($this->c, $query);
    while ($row = mysqli_fetch_array($select)) {
        $data[] = array(
            'name' => $row['platform'],
            'num' => $row['num']
        );
    }
    return $data;
}

array (
    '0' => array ('name' => 'linux', 'num' => 3)
    '1' => array ('name' => 'windows', 'num' => 3)
);

---

因为您的数据库中没有任何mac或未知数据，所以您将无法在此平台上获得任何结果，甚至0也无法。您可以做的是使用您希望获得的平台预先配置阵列：

$data = array(
   'windows' => 0, 
   'linux' => 0,
   'mac' => 0,
   'unknown' => 0
)

现在在

get\u platforms

函数中执行以下操作：

function get_platforms() {
    $query = "
            SELECT platform, COUNT(platform) AS num 
            FROM stats 
            GROUP BY platform 
            ORDER BY platform ASC
            ";
    $select = mysqli_query($this->c, $query);
    while ($row = mysqli_fetch_array($select)) {
        $data[$row['platform']] = $row['num'];
    }
    return $data;
}

$result = array();
foreach($data as $platform => $count){
    $result[] = array('name' => $platform, 'count' => $count);
}

您将得到以下结果：

$data = array(
   'windows' => 3, 
   'linux' => 3,
   'mac' => 0,
   'unknown' => 0
)

然后你可以按照你想要的方式重新格式化数据。例如，您可以执行以下操作：

function get_platforms() {
    $query = "
            SELECT platform, COUNT(platform) AS num 
            FROM stats 
            GROUP BY platform 
            ORDER BY platform ASC
            ";
    $select = mysqli_query($this->c, $query);
    while ($row = mysqli_fetch_array($select)) {
        $data[$row['platform']] = $row['num'];
    }
    return $data;
}

$result = array();
foreach($data as $platform => $count){
    $result[] = array('name' => $platform, 'count' => $count);
}

---

您将得到与您要求的格式相同的结果。

首先，您应该定义所需输出的顺序，假设您有一个数组

$osList = array('linux', 'windows', 'mac', 'something');

现在将mysql结果提取到临时assoc数组：

$data = array();
$query = "SELECT platform, COUNT(platform) AS num"
    . " FROM stats"
    . " GROUP BY platform";
$result = mysqli_query($this->c, $query);
while ($row = mysqli_fetch_array($result)) {
    $data[$row['platform']] = (int) $row['num'];        
}

在这里，您可以形成输出数组：

$output = array();
foreach ($osList as $os) {
    $output[] = array(
        'name' => $os,
        'count' => isset($data[$os]) ? $data[$os] : 0
    );
}

---

您必须有另一个表，其中列出了所有平台。例如，我们称之为

platforms

，它有一列

platform\u name

，其中包含所有平台（包括mac）的唯一名称，那么查询将是：

SELECT platforms.`platform_name`, COUNT(stats.`platform`) FROM `platforms`
LEFT JOIN `stats` ON  platforms.`platform_name` = stats.`platform`
GROUP BY platforms.`platform_name`

---

是否有任何表或数组具有预定义的

平台列表

？@Rikesh我在收集数据的php函数中有数组。数组是：[windows、linux、mac、未知]您的第一个数组

$platforms

应命名为

$data

，因此函数将替换值。