我最近开始学习PHP中的面向对象，我有了这个小代码。我在class.php中有这个代码：
## Teacher
class Teacher
{
public $_id;
public $_name;
public $_phone;
public function create($id, $name, $phone) {
$this->_id = $id;
$this->_name = $name;
$this->_phone = $phone;
}
}
## Lesson
class Lesson
{
public $_teacher;
public $_student;
public $_price;
public $_date;
public function create($teacher,$student,$price,$date)
{
$this->_teacher = $teacher;
$this->_student = $student;
$this->_price = $price;
$this->_date = $date;
}
}
mysql.php：
## MySQL Database Connection
$host = "localhost";
$username = "root";
$password = "";
$dbname = "foo";
// Create connection
$conn = new mysqli($host, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
} else {
echo "Connected successfully";
}
// Create database
$sql = "CREATE DATABASE $dbname";
// sql to create table
$sql = "CREATE TABLE teachers (
id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,
firstname VARCHAR(30) NOT NULL,
lastname VARCHAR(30) NOT NULL,
phone VARCHAR(50)
)";
$conn->query($sql);
我在index.php中有这个：
include_once('mysql.php');
include_once('class.php');
## PHP Code
$teacher1 = new Teacher();
$teacher1->create(324,"Ben","054","Audi TT");
var_dump($teacher1);
## PHP Code
$lesson1 = new Lesson();
$lesson1->create($teacher1->_id,date("D d/m/Y H:i"),240,2);
var_dump($lesson1);
每当我在教师对象中使用create（）方法时，我都想对数据库做一些事情（例如插入）。
正确的做法是什么？
-我需要在每个方法中创建一个新的mysqli对象吗
顺便说一句，对我的代码进行一次小小的审查将是史诗般的。比如，我很想知道我是否做对了。
您可以这样做：
private $connections = array();
public function newConnection( $host, $user, $password, $database )
{
$this->connections[] = new mysqli( $host, $user, $password, $database );
$connection_id = count( $this->connections )-1;
if( mysqli_connect_errno() )
{
trigger_error('Error connecting to host. '.$this->connections[$connection_id]->error, E_USER_ERROR);
}
return $connection_id;
}
public function closeConnection()
{
$this->connections[$this->activeConnection]->close();
}
public function insertRecords( $table, $data )
{
// setup some variables for fields and values
$fields = "";
$values = "";
// populate them
foreach ($data as $f => $v)
{
$fields .= "`$f`,";
$values .= ( is_numeric( $v ) && ( intval( $v ) == $v ) ) ? $v."," : "'$v',";
}
// remove our trailing ,
$fields = substr($fields, 0, -1);
// remove our trailing ,
$values = substr($values, 0, -1);
$insert = "INSERT INTO $table ({$fields}) VALUES({$values})";
//echo $insert;
$this->executeQuery( $insert );
}
public function executeQuery( $queryStr )
{
if( !$result = $this->connections[$this->activeConnection]->query( $queryStr ) )
{
trigger_error('Error executing query: ' . $queryStr .' - '.$this->connections[$this->activeConnection]->error, E_USER_ERROR);
}
else
{
$this->last = $result;
}
}