Memcached::add() 函數是 PHP 中 memcached 類的內置函數,用於在 memcache 服務器上設置/添加具有過期時間 (TTL) 的給定值下的給定值。此函數類似於 Memcached::set() 函數,但如果服務器上已存在 key ,則操作失敗。
用法:
public Memcached::add( $key, $value, $expiration = ?):bool
參數:該函數接受三個參數:
- key:存儲值的鍵。
- value:要存儲的值。
- expiration:過期時間,默認為 0。有關更多信息,請參閱過期時間。
返回值:如果鍵值對存儲成功,此函數返回 true,如果失敗則返回 false。如果鍵已經存在,則 Memcached::getResultCode() 函數將返回 Memcached::RES_NOTSTORED。
下麵的例子說明了 PHP 中的 Memcached::add() 函數:
範例1:
PHP
<?php
echo "<pre>";
// Server & port details
$server = '127.0.0.1';
$port = 11211;
// Initiate a new object of memcache
$memcacheD = new Memcached();
// Add server
if ($memcacheD->addServer($server, $port)) {
echo "** server added ** \n";
}
else {
echo "** issue while creating a server **\n";
}
// Set key & value with TTL
$key = "GEEKSFORGEEKS";
$value = "computer science portal";
$ttl = 3600;
if ($memcacheD->add($key, $value, $ttl))
echo "** added key-value (" . $key . ":"
. $value . ")to cache successfully!! **\n";
else
echo "** error while adding value to cache!! **\n";
// Get value of key
echo "**** FETCHED VALUE FOR KEY:"
. $key . " ****\n";
$valD = $memcacheD->get($key);
var_dump($valD);
?>
輸出:
** server added **
** added key-value (GEEKSFORGEEKS:computer science portal)to cache successfully!! **
**** FETCHED VALUE FOR KEY:GEEKSFORGEEKS ****
string(23) “computer science portal”
示例 2(已經存在的 key-pair):
PHP
<?php
echo "<pre>";
// Server & port details
$server = '127.0.0.1';
$port = 11211;
// Initiate a new object of memcache
$memcacheD = new Memcached();
// Add server
if ($memcacheD->addServer($server, $port)) {
echo "** server added ** \n";
}
else {
echo "** issue while creating a server **\n";
}
// Set key & value with TTL
$key = "GEEKSFORGEEKS";
$value = "computer science portal";
$ttl = 3600;
if ($memcacheD->add($key, $value, $ttl))
echo "** added key-value (" . $key . ":"
. $value . ")to cache successfully!! **\n";
else
echo "** error while adding value to cache!! **\n";
// Get value of key
echo "**** FETCHED VALUE FOR KEY:"
. $key . " ****\n";
$valD = $memcacheD->get($key);
var_dump($valD);
?>
輸出:
** server added **
** error while adding value to cache!!::MSG::NOT STORED **
**** FETCHED VALUE FOR KEY:geeksforgeeks ****
string(23) “computer science portal”
參考: https://www.php.net/manual/en/memcached.add.php
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注:本文由純淨天空篩選整理自Shivam.Pradhan大神的英文原創作品 PHP Memcached add() Function。非經特殊聲明,原始代碼版權歸原作者所有,本譯文未經允許或授權,請勿轉載或複製。