php封装MySQL的数据操作的功能查询结果
php封装MySQL的数据操作的功能查询结果代码如下：
<?php
//封装MySQL单例
class MySQLDB {
private $host; //主机地址
private $port; //端口号
private $user; //用户名
private $pwd; //密码
private $dbname; //数据接名
private $charset; //字符集
private $link; //连接对象
private static $instance;
private function __construct($param) {
$this->initParam($param);
$this->initConnect();
}
private function __clone() {
}
//获取单例
public static function getInstance($param=array()) {
if(!self::$instance instanceof self)
self::$instance=new self($param);
return self::$instance;
}
//初始化参数
private function initParam($param) {
$this->host=$param['host']??'127.0.0.1';
$this->port=$param['port']??'3306';
$this->user=$param['user']??'';
$this->pwd=$param['pwd']??'';
$this->dbname=$param['dbname']??'';
$this->charset=$param['charset']??'utf8';
}
//连接数据库
private function initConnect() {
$this->link=@mysqli_connect($this->host,$this->user,$this->pwd,$this->dbname);
if(mysqli_connect_error()){
echo '数据库连接失败<br>';
echo '错误信息：'.mysqli_connect_error(),'<br>';
echo '错误码：'.mysqli_connect_errno(),'<br>';
exit;
}
mysqli_set_charset($this->link,$this->charset);
}
//执行数据库的增、删、改、查
private function execute($sql) {
if(!$rs=mysqli_query($this->link,$sql)){
echo 'SQL语句执行失败<br>';
echo '错误信息：'.mysqli_error($this->link),'<br>';
echo '错误码：'.mysqli_errno($this->link),'<br>';
echo '错误的SQL语句：'.$sql,'<br>';
exit;
}
return $rs;
}
/**
*执行增、删、改
*@return bool 成功返回true,失败返回false
*/
public function exec($sql) {
$key=substr($sql,0,6);
if(in_array($key,array('insert','update','delete')))
return $this->execute($sql);
else{
echo '非法访问<br>';
exit;
}
}
//获取自动增长的编号
public function getLastInsertId() {
return mysqli_insert_id($this->link);
}
//执行查询语句
private function query($sql) {
if(substr($sql,0,6)=='select' || substr($sql,0,4)=='show' || substr($sql,0,4)=='desc'){
return $this->execute($sql);
}else{
echo '非法访问<br>';
exit;
}
}
/**
*执行查询语句，返回二维数组
*@$sql string 查询sql语句
*@type string assoc|num|both
*/
public function fetchAll($sql,$type='assoc') {
$rs=$this->query($sql);
$type=$this->getType($type);
return mysqli_fetch_all($rs,$type);
}
//匹配一维数组
public function fetchRow($sql,$type='assoc') {
$list=$this->fetchAll($sql,$type);
if(!empty($list))
return $list;
return array();
}
//匹配一行一列
public function fetchColumn($sql) {
$list=$this->fetchRow($sql,'num');
if(!empty($list))
return $list;
return null;
}
//获取匹配类型
private function getType($type) {
switch($type){
case 'num':
returnMYSQLI_NUM;
case 'both':
returnMYSQLI_BOTH;
default:
returnMYSQLI_ASSOC;
}
}
}
//测试
//配置参数
$param=array(
'user' => 'root',
'pwd' => 'root',
'dbname' => 'data'
);
//获取单例
$db=MySQLDB::getInstance($param);
//更新
//$db->exec("update news set title='青草' where id=2");
//插入
/*
if($db->exec("insert into news values (null,'aa','bb',unix_timestamp())"))
echo '编号是：'.$db->getLastInsertId();
*/
//查询
//$list=$db->fetchAll('select * from news','aa');
//$list=$db->fetchRow('select * from news where id=1','aa');
$list=$db->fetchColumn('select count(*) from news');
echo '<pre>';
var_dump($list);
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