匹配mysql列的多维数组

Question

我有一个包含行业和类别的表格如下所示。

id|industry|category        |
1 |Building|Air Conditioning|
2 |Building|Roofing         |
3 |Security|Cameras         |

我正在尝试按如下方式返回数组

   array(
    "Building" => array(
        "Air Conditioning",
        "Roofing",
    ),
    "Security" => array(
        "Cameras",
    ),
);

解决此问题的最佳方法是什么。

感谢您提前提供任何帮助。

Answer 1

试试这个：

$query = mysql_query('select * from table');
foreach ($data = mysql_fetch_object($query)) {
    $array[$data->industry][] = $data->category;
}

print_r($array);

Answer 2

只需对数据进行一次迭代：

$data = [
    [1, "Building", "Air Conditioning"],
    [2, "Building", "Roofing"],
    [3, "Security", "Cameras"]
];
$result = [];
foreach ($data as $row) {
    if (!array_key_exists($row[1], $result)) {
        $result[$row[1]] = [];
    }
    array_push($result[$row[1]], $row[2]);
}
var_dump($result);

Link to Fiddle

Answer 3

$tbl_industries = array(
    array(
        'id' => 1,
        'industry' => 'Building',
        'category' => 'Air Conditioning'
    ),
    array(
        'id' => 2,
        'industry' => 'Building',
        'category' => 'Roofing'
    ),
    array(
        'id' => 3,
        'industry' => 'Security',
        'category' => 'Cameras'
    )
);

foreach($tbl_industries as $industry) {
    $industry_name = $industry['industry'];
    $industries[$industry_name][] = $industry['category'];
}

var_dump($industries);

或

包含数据库交互的代码：

$con = mysqli_connect('localhost', 'root', '', 'db_name');
$query = "SELECT * FROM tbl_industries";

if($result = mysqli_query($con, $query)) {
    while($industry = mysqli_fetch_assoc($result)) {
        $industry_name = $industry['industry'];
        $industries[$industry_name][] = $industry['category'];
    }

    mysqli_free_result($result);        
    var_dump($industries);
}