php - mysql_fetch_assoc时如何在循环中进行php排序？

Question

这是我的查询：

$query=mysql_query("select * from people order by birth asc");
while($r=mysql_fetch_assoc($query)){
    $birth=$r['birth'];
    if($r['addmonth']=="2") {
        $birth=date("d-m-Y", strtotime("$birth+2 month")); //additional months on date of birth
    }

    echo"$r[name] $birth";
}

如何使用 $birth ASC 返回的 php 进行排序

Answer 1

更改您的查询以增加数据库中的月份，因此您无需再次对行进行排序：

SELECT *, CASE WHEN (addmonth = 2) THEN (birth + INTERVAL 2 MONTH) ELSE (birth) END AS birth_order FROM people ORDER BY birth_order ASC

---

编辑：

另一种选择是在 SQL 上不更改地检索数组，并使用usort：

$people = array();
$result = mysql_query("SELECT * FROM people ORDER BY birth ASC");

if ($result) {
    while ($r = mysql_fetch_assoc($result)) {
        $people []= $r;
    }

    mysql_free_result($result);
}

$calculate_date = function ($person) {
    $date = $person['birth'];

    if ($person['addmonth'] == 2) {
        $date += '+2 month';
    }

    return $date;
};

usort($people,function($a,$b)use($calculate_date){
    return $calculate_date($a) > $calculate_date($b);
});