php如何在mysql_fetch_assoc中進行循環排序？

Question

這是我的查詢：

$query=mysql_query("select * from people order by birth asc"); 
while($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"; 
} 

如何排序由$誕生ASC

Answer 1

更改您的查詢增加個月的DB，這樣你就不會需要再訂購返回的行PHP ：

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

---

編輯：

另一種選擇是檢索，而不在SQL改變數組，並使用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); 
});