本文實例講述了php封裝的mysqli類。分享給大家供大家參考，具體如下：
類：?? ?
<?php
header('content-type:text/html;charset=utf-8');
/*
掌握滿足單例模式的必要條件
(1)私有的構造方法-為了防止在類外使用new關鍵字實例化對象
(2)私有的成員屬性-為了防止在類外引入這個存放對象的屬性
(3)私有的克隆方法-為了防止在類外通過clone成生另一個對象
(4)公有的靜態方法-為了讓用戶進行實例化對象的操作
*/
class ConnectMysqli{
? //私有的屬性
? private static $dbcon=false;
? private $host;
? private $port;
? private $user;
? private $pass;
? private $db;
? private $charset;
? private $link;
? //私有的構造方法
? private function __construct($config=array()){
??? $this->host = $config['host'] ? $config['host'] : 'localhost';
??? $this->port = $config['port'] ? $config['port'] : '3306';
??? $this->user = $config['user'] ? $config['user'] : 'root';
??? $this->pass = $config['pass'] ? $config['pass'] : 'root';
??? $this->db = $config['db'] ? $config['db'] : 'small2';
??? $this->charset=isset($arr['charset']) ? $arr['charset'] : 'utf8';
??? //連接數據庫
??? $this->db_connect();
??? //選擇數據庫
??? $this->db_usedb();
??? //設置字符集
??? $this->db_charset();
?? }
?? //連接數據庫
?? private function db_connect(){
??? $this->link=mysqli_connect($this->host.':'.$this->port,$this->user,$this->pass);
??? if(!$this->link){
????? echo "數據庫連接失敗<br>";
????? echo "錯誤編碼".mysqli_errno($this->link)."<br>";
????? echo "錯誤信息".mysqli_error($this->link)."<br>";
????? exit;
??? }
?? }
?? //設置字符集
??? private function db_charset(){
???? mysqli_query($this->link,"set names {$this->charset}");
??? }
??? //選擇數據庫
?? private function db_usedb(){
???? mysqli_query($this->link,"use {$this->db}");
?? }
?? //私有的克隆
?? private function __clone(){
???? die('clone is not allowed');
?? }
?? //公用的靜態方法
?? public static function getIntance(){
???? if(self::$dbcon==false){
????? self::$dbcon=new self;
???? }
???? return self::$dbcon;
?? }
?? //執行sql語句的方法
??? public function query($sql){
???? $res=mysqli_query($this->link,$sql);
???? if(!$res){
????? echo "sql語句執行失敗<br>";
????? echo "錯誤編碼是".mysqli_errno($this->link)."<br>";
????? echo "錯誤信息是".mysqli_error($this->link)."<br>";
???? }
???? return $res;
?? }
?? //打印數據
??? public function p($arr){
????? echo "<pre>";
????? print_r($arr);
????? echo "</pre>";
??? }
??? public function v($arr){
??? echo "<pre>";
????? var_dump($arr);
????? echo "</pre>";
??? }
??? //獲得最后一條記錄id
??? public function getInsertid(){
???? return mysqli_insert_id($this->link);
??? }
?? /**
??? * 查詢某個字段
??? * @param
??? * @return string or int
??? */
??? public function getOne($sql){
???? $query=$this->query($sql);
????? return mysqli_free_result($query);
??? }
??? //獲取一行記錄,return array 一維數組
??? public function getRow($sql,$type="assoc"){
???? $query=$this->query($sql);
???? if(!in_array($type,array("assoc",'array',"row"))){
?????? die("mysqli_query error");
???? }
???? $funcname="mysqli_fetch_".$type;
???? return $funcname($query);
??? }
??? //獲取一條記錄,前置條件通過資源獲取一條記錄
??? public function getFormSource($query,$type="assoc"){
??? if(!in_array($type,array("assoc","array","row")))
??? {
????? die("mysqli_query error");
??? }
??? $funcname="mysqli_fetch_".$type;
??? return $funcname($query);
??? }
??? //獲取多條數據，二維數組
??? public function getAll($sql){
???? $query=$this->query($sql);
???? $list=array();
???? while ($r=$this->getFormSource($query)) {
????? $list[]=$r;
???? }
???? return $list;
??? }
???? /**
???? * 定義添加數據的方法
???? * @param string $table 表名
???? * @param string orarray $data [數據]
???? * @return int 最新添加的id
???? */
???? public function insert($table,$data){
???? //遍歷數組，得到每一個字段和字段的值
???? $key_str='';
???? $v_str='';
???? foreach($data as $key=>$v){
????? if(empty($v)){
?????? die("error");
???? }
??????? //$key的值是每一個字段s一個字段所對應的值
??????? $key_str.=$key.',';
??????? $v_str.="'$v',";
???? }
???? $key_str=trim($key_str,',');
???? $v_str=trim($v_str,',');
???? //判斷數據是否為空
???? $sql="insert into $table ($key_str) values ($v_str)";
???? $this->query($sql);
??? //返回上一次增加操做產生ID值
???? return $this->getInsertid();
?? }
?? /*
??? * 刪除一條數據方法
??? * @param1 $table, $where=array('id'=>'1') 表名 條件
??? * @return 受影響的行數
??? */
??? public function deleteOne($table, $where){
????? if(is_array($where)){
??????? foreach ($where as $key => $val) {
????????? $condition = $key.'='.$val;
??????? }
????? } else {
??????? $condition = $where;
????? }
????? $sql = "delete from $table where $condition";
????? $this->query($sql);
????? //返回受影響的行數
????? return mysqli_affected_rows($this->link);
??? }
??? /*
??? * 刪除多條數據方法
??? * @param1 $table, $where 表名 條件
??? * @return 受影響的行數
??? */
??? public function deleteAll($table, $where){
????? if(is_array($where)){
??????? foreach ($where as $key => $val) {
????????? if(is_array($val)){
??????????? $condition = $key.' in ('.implode(',', $val) .')';
????????? } else {
??????????? $condition = $key. '=' .$val;
????????? }
??????? }
????? } else {
??????? $condition = $where;
????? }
????? $sql = "delete from $table where $condition";
????? $this->query($sql);
????? //返回受影響的行數
????? return mysqli_affected_rows($this->link);
??? }
?? /**
??? * [修改操作description]
??? * @param [type] $table [表名]
??? * @param [type] $data [數據]
??? * @param [type] $where [條件]
??? * @return [type]
??? */
?? public function update($table,$data,$where){
???? //遍歷數組，得到每一個字段和字段的值
???? $str='';
??? foreach($data as $key=>$v){
???? $str.="$key='$v',";
??? }
??? $str=rtrim($str,',');
??? //修改SQL語句
??? $sql="update $table set $str where $where";
??? $this->query($sql);
??? //返回受影響的行數
??? return mysqli_affected_rows($this->link);
?? }
}
?>

用法測試：?? ?
//mysqli測試
$db=ConnectMysqli::getIntance();
//var_dump($db);
/*$sql="select * from acticle";
$list=$db->getAll($sql);
$db->p($list);*/
/*$sql="select * from acticle where acticle_id=95";
$list=$db->getRow($sql);
$db->p($list);
*/
/*$sql="select title from acticle";
$list=$db->getOne($sql);
$db->p($list);不行*/
//$list=$db->insert("users",$_POST);
//$del=$db->deleteOne("users","id=29");
//$del=$db->deleteAll("users","id in(27,28)");
//$up=$db->update("users",$_POST,"id=27");
//print_R($list);

來源:http://www.thinkphp.cn/topic/50610.html

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