public static function getInstance()
{
if (NULL === self::$instance) {
self::$instance = new self();
}
return self::$instance;
}
public static function getInstance()
{
if (self::$instance == null) {
self::$instance = new singleton();
}
return self::$instance;
}
public static function getInstance(&$sql, $location, $var, $type)
{
// 确定类型
switch ($type) {
default:
// 默认使用字符串类型
// 默认使用字符串类型
case 'STRING':
$var = addslashes($var);
// 转义
$var = "'" . $var . "'";
// 加上单引号.sql语句中字符串插入必须加单引号
break;
case 'INTEGER':
case 'INT':
$var = (int) $var;
// 强制转换成int
// 还可以增加更多的类型...
}
$pos = 0;
// 判断该类是否是第一次被实例化
if (self::$instance == NULL) {
self::$instance = new singleton();
for ($i = 1; $i <= $location; $i++) {
$pos = strpos($sql, '?', $pos + 1);
}
} else {
for ($i = 1; $i <= $location - 1; $i++) {
$pos = strpos($sql, '?', $pos + 1);
}
}
return $sql = substr($sql, 0, $pos) . $var . substr($sql, $pos + 1);
}
/**
* This function returns a instance (and creates a new one
* if there isnt already one) of a class.
*
* @author Johannes Klose <*****@*****.**>
* @param string $class Class from where an instance should be returned.
* @return object Instance of $class
**/
function &singleton($class)
{
static $singleton;
if (!is_object($singleton)) {
$singleton = new singleton();
}
return $singleton->instance($class);
}
public static function singleton($username, $password) {
if (!(self::$instance)) {
$className = __CLASS__;
self::$instance = new Mongo("mongodb://${username}:${password}@localhost/test", array("persist" => "x"));
;
}
return self::$instance;
}
