我在運行時創建數據庫和表。當我執行代碼時，它正在創建數據庫而不是表。它拋出一個錯誤：“沒有選擇數據庫”；請指導我。$sql = "CREATE DATABASE $db_name";if ($this->db->query($sql) === TRUE) {    $errors = [];    $table1 = "CREATE TABLE `login_detail` (                `id` int(100)  UNSIGNED AUTO_INCREMENT PRIMARY KEY,                `employee_id` varchar(100) NOT NULL,                `full_name` varchar(150) NOT NULL,                `password` varchar(100) NOT NULL,                `role` varchar(50) NOT NULL,                `profile_image` varchar(255) NOT NULL,                `status` varchar(100) NOT NULL DEFAULT '1')";    $table2 = "INSERT INTO `login_detail`                         (`id`, `employee_id`, `full_name`,                         `password`, `role`, `profile_image`, `status`)                 VALUES (1, 'admin', 'admin',                         '21232f297a57a5a743894a0e4a801fc3', 'admin',                         'uploads/profiles/admin.jpg', '1')";    $tables = [$table1, $table2];    foreach($tables as $k => $sql1){        $query = $this->db->query($sql1);        if(!$query)            $errors[] = "Table $k : Creation failed ($this->db->error)";        else            $errors[] = "Table $k : Creation done";    }    foreach($errors as $msg) {        echo "$msg <br>";    }} else {    echo "Error creating database: " . $this->db->error;}