php－－-数据库类封装

<?php

   class SqlTool{
      private $conn;
      private $username="root";
      private $password="1234";
      private $host="127.0.0.1";
      private $db="test";
     
     function SqlTool(){
        $this->conn=mysql_connect($this->host,$this->username,$this->password);
        if(!$this->conn)
        {
            die  ("连接失败".mysql_error($this.conn));
        }
        mysql_select_db($this->db,$this->conn);
        mysql_query("set names utf8");
     }
     
     //完成select
     function execute_dql($sql)
     {
        $result = mysql_query($sql,$this->conn);
        $arrTemp = array();
        $counter = 0;
        while($row = mysql_fetch_assoc($result))
        {
         $arrTemp[$counter] = $row;
          $counter++;
        }
        mysql_free_result($result);
        mysql_close($this->conn);
        
        return json_encode($arrTemp);
     }
     
     //完成dml
     public  function execute_dml($sql)
     {
        $res=mysql_query($sql,$this->conn);
        if(!$res)
        {
            return 0; //执行失败
        } 
        else
        {
            if(mysql_affected_rows($this->conn)>0)
            { 
                return 1;  //执行成功
            } 
            else
            {
                return 2; //没有行数收到影响
            }
        }
        
     }
   } 

?>

<?php
 
  @header("content-Type:text/html;charset:utf-8");
 
  require_once "SqlTool.class.php";
  $sqlStr = "insert into student(number,name,age) values('200911230','huzhuxi','45');";
  $sqlTool = new SqlTool();
  $result1=$sqlTool->execute_dml($sqlStr);
  echo "结果为:".$result1."<br/>";
  
  $sqlStr1 = "select * from student";
  $resultStr = $sqlTool->execute_dql($sqlStr1);
  echo "当前数据：<br/>".$resultStr;
?>