PHP 对MySQLI预处理的包装

<?php

class Mysql {

private static $instance;
private $link;
private $query;
private $stmt;
private $param;

// 初始化
private function __construct() {
$this->link = @new mysqli('localhost', 'root', 'chenshuo90909', 'temp');
if(mysqli_connect_errno()) {
echo "MySQL connect error!"; exit();
}
return $this->link;
}

// 单例模式
public static function instance() {
if(isset(self::$instance)){
return self::$instance;
} else {
self::$instance = new self();
return self::$instance;
}
}

// 预处理SQL
private function prepare($query) {
$this->query = $query;
$this->stmt = $this->link->prepare($this->query);
if($this->stmt) {
return $this->stmt;
} else {
echo "Stmt error!"; exit;
}
}

// 值绑定
private function bind_value($array) {
$data = array();
foreach ($array as $key => $value) {
$data[$key] = &$array[$key];
}
return $data;
}

// 执行
public function execute($query, $param) {
$this->query = $query;
$this->stmt = $this->link->prepare($this->query);
$this->param = $param;
call_user_func_array(array($this->stmt, 'bind_param'), $this->bind_value($this->param));    //绑定参数
$result = $this->stmt->execute();
var_dump($result);
}

// 返回单挑数据
public function find($query, $param) {
$this->query = $query;
$this->param = $param;
$this->stmt = $this->link->prepare($this->query);
//绑定参数
call_user_func_array(array($this->stmt, 'bind_param'), $this->bind_value($this->param));
$this->stmt->execute();

$meta = $this->stmt->result_metadata();
// 将结果绑定数组元素设置为引用状态
while ($field = $meta->fetch_field()) {
$parameters[] = &$row[$field->name];
}
//绑定结果
call_user_func_array(array($this->stmt, 'bind_result'), $this->bind_value($parameters));

while ($this->stmt->fetch()) {
$result = $row;
}

return $result;
}

// 返回多条数据
public function fetch($query, $param) {
$this->query = $query;
$this->param = $param;
$this->stmt = $this->link->prepare($this->query);

//绑定参数
call_user_func_array(array($this->stmt, 'bind_param'), $this->bind_value($this->param));
$this->stmt->execute();

$meta = $this->stmt->result_metadata();

// 将结果绑定数组元素设置为引用状态
while ($field = $meta->fetch_field()) {
$parameters[] = &$row[$field->name];
}

//绑定结果
call_user_func_array(array($this->stmt, 'bind_result'), $this->bind_value($parameters));

// 有多行记录时将多行记录存入$results数组中.
while ($this->stmt->fetch()) {
$data = array();
foreach ($row as $key => $value) {
$data[$key] = $value;
}
$result[] = $data;
}

return $result;
}

// SQL语句调试
public function debug() {
return $this->query;
}

// 释放资源
public function __destruct() {
$this->stmt->close();
$this->link->close();
}

}

?>

<?php
include 'mysql.php';
class Data {

const INSERT = "INSERT INTO user (username, password)VALUES(?, ?)";
const UPDATE = "UPDATE user SET username = ? WHERE uid = ?";
const SELECT = "SELECT username, password FROM user WHERE username = ? AND password = ?";
const DELETE = "DELETE FROM user WHERE uid = ?";

private $db;

public function __construct() {
$this->db = Mysql::instance();
}

public function insert($username, $password) {
$query = self::INSERT;
$param = array('ss',$username, $password);
$result = $this->db->execute($query, $param);
return $result;
}

public function delete($uid) {
$query = self::DELETE;
$param = array('i',$uid);
$result = $this->db->execute($query, $param);
return $result;
}

public function update($username, $uid) {
$query = self::UPDATE;
$param = array('si',$username, $uid);
$result = $this->db->execute($query, $param);
return $result;
}

public function select($username, $password) {
$query = self::SELECT;
$param = array('ss',$username, $password);
$result = $this->db->find($query, $param);
return $result;
}

public function find($username, $password) {
$query = self::SELECT;
$param = array('ss',$username, $password);
$result = $this->db->find($query, $param);
return $result;
}

}

$data = new Data();

//$data->insert('chenshuox', 'chenshuo123');
//$data->delete(2);
//$data->update('tinys123', 1);

$result = $data->find('chenshuox', 'chenshuo123');
echo $result['username'];
echo $result['password'];

?>