<?php

 $db = array(

         'host'=>'localhost',

         'user'=>'root',

         'password'=>'********',

         'database'=>'test',

 )

 ?>

 <?php

     class db {

         public $conn;

         public static $sql;

         public static $instance=null;

         private function __construct(){

             require_once('db.config.smarty.php');

             $this->conn = mysql_connect($db['host'],$db['user'],$db['password']);

             if(!mysql_select_db($db['database'],$this->conn)){

                 echo "失败";

             };

             mysql_query('set names utf8',$this->conn);

         }

         public static function getInstance(){

             if(is_null(self::$instance)){

                 self::$instance = new db;

             }

             return self::$instance;

         }

         /**

          * 查询数据库

          */

         public function select($table,$condition=array(),$field = array()){

             $where='';

             if(!empty($condition)){

                 foreach($condition as $k=>$v){

                     $where.=$k."='".$v."' and ";

                 }

                 $where='where '.$where .'1=1';

             }

             $fieldstr = '';

             if(!empty($field)){

                 foreach($field as $k=>$v){

                     $fieldstr.= $v.',';

                 }

                  $fieldstr = rtrim($fieldstr,',');

             }else{

                 $fieldstr = '*';

             }

             self::$sql = "select {$fieldstr} from {$table} {$where}";

             $result=mysql_query(self::$sql,$this->conn);

             $resuleRow = array();

             $i = 0;

             while($row=mysql_fetch_assoc($result)){

                 foreach($row as $k=>$v){

                     $resuleRow[$i][$k] = $v;

                 }

                 $i++;

             }

             return $resuleRow;

         }

         /**

          * 添加一条记录

          */

          public function insert($table,$data){

              $values = '';

              $datas = '';

              foreach($data as $k=>$v){

                  $values.=$k.',';

                  $datas.="'$v'".',';

              }

              $values = rtrim($values,',');

              $datas   = rtrim($datas,',');

              self::$sql = "INSERT INTO  {$table} ({$values}) VALUES ({$datas})";

             if(mysql_query(self::$sql)){

                 return mysql_insert_id();

             }else{

                 return false;

             };

          }

          /**

           * 修改一记录

           */

         public function update($table,$data,$condition=array()){

             $where='';

             if(!empty($condition)){

                 foreach($condition as $k=>$v){

                     $where.=$k."='".$v."' and ";

                 }

                 $where='where '.$where .'1=1';

             }

             $updatastr = '';

             if(!empty($data)){

                 foreach($data as $k=>$v){

                     $updatastr.= $k."='".$v."',";

                 }

                 $updatastr = 'set '.rtrim($updatastr,',');

             }

             self::$sql = "update {$table} {$updatastr} {$where}";

             return mysql_query(self::$sql);

         }

         /**

          * 删除记录

          */

          public function delete($table,$condition){

              $where='';

             if(!empty($condition)){

                 foreach($condition as $k=>$v){

                     $where.=$k."='".$v."' and ";

                 }

                 $where='where '.$where .'1=1';

             }

             self::$sql = "delete from {$table} {$where}";

             return mysql_query(self::$sql);

          }

         public static function getLastSql(){

             echo self::$sql;

         }

     }

    ?>

 //require_once 'db.conn.smarty.php';
0 //$db = db::getInstance();
1 //$arr = array(9 => 'Tennis', 3 => 'Swimming', 8 => 'Coding');

 //$arr = $db->select('demo',array('password'=>'yujianqi2011'),array('username','age'));

 //echo $db->insert('demo',array('name'=>'最近你啦','password'=>'123'));

 //echo $db->update('demo',array("name"=>'xxx',"password"=>'123'),array('id'=>1));

5 //echo $db->delete('demo',array('id'=>'2'));

 //db::getLastSql();

 //echo $list;