class Database {
public $isConn;
private static $_instance = null;
private $datab;
// connect to db
public function __construct($username = "root", $password = "", $host = "localhost", $dbname = "market", $options = []) {
$this->isConn = TRUE;
try {
$this->datab = new PDO("mysql:host={$host};dbname={$dbname};charset=utf8", $username, $password, $options);
$this->datab->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$this->datab->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC);
} catch (PDOException $e) {
throw new Exception($e->getMessage());
}
}
public static function getInstance() {
if (!isset(self::$_instance)) {
self::$_instance = new Database();
}
return self::$_instance;
}
现在在每个需要数据库连接的类中
class test {
private $_db = null;
public function __construct() {
$this->_db = Database::getInstance();
}
public function test(){
return $this->_db->getRow("SELECT * FROM users", PDO::FETCH_ASSOC, []);
}
public static function testStatic(){
return $this->_db->getRow("SELECT * FROM users", PDO::FETCH_ASSOC, []);
}
现在它给了我一个错误,说不能使用$this,那么我如何使用self :: ??
}
现在我如何在静态函数和非静态函数中一起使用它
解决方法:
在需要时获取数据库实例.
class test {
public function test(){
return Database::getInstance()->getRow("SELECT * FROM users", PDO::FETCH_ASSOC, []);
}
public static function testStatic(){
return Database::getInstance()->getRow("SELECT * FROM users", PDO::FETCH_ASSOC, []);
}
}
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