[php]mysql操作流程

这种是比较老的一种mysql连接方法

1、连接数据库

$this->con = mysql_connect($this->host, $this->user, $this->pswd);

2、选择数据库

mysql_select_db($this->db, $this->con);

3、操作

mysql_query($sql, $this->con);

4、释放资源

mysql_free_result($this->res);
mysql_close($this->con);

面向对象的写法如下：

<?php
    class SQL{
        private static $con;
        private static $host = "localhost";
        private static $user = "root";
        private static $pswd = "root";
        private static $db = "test";
        private static $res;
        SQL()
        {
            $this->con = mysql_connect($this->host, $this->user, $this->pswd);
            if(!$this->con)
                die("CON ERROR:".mysql_errno().mysql_error());
            $bool = mysql_select_db($this->db, $this->con);
            if($bool)
                die("MYSQL_SELECT_DB ERROR:".mysql_errno().mysql_error());
            mysql_query("set names utf8");
        }
        /*set host, db, user, password*/
        function set_attr($host, $db, $user, $pswd){
            $this->host = $host;
            $this->db = $db;
            $this->user = $user;
            $this->pswd = $pswd;
        }
        /*add update delete and so on*/
        function execute($sql){
            $bool = mysql_query($sql, $this->con);
            if(!$bool)
                die("MYSQL_SELECT ERROR:".mysql_errno().mysql_error());
            else{
                if(mysql_affected_rows($this->con))
                    return 0;//now rows affect
                else
                    return 1;//success
            }
        }
        /*select*/
        function execute_query($sql){
            $res = mysql_query($sql, $this->con) or die("MYSQL_QUERY ERROR:".mysql_errno().mysql_error());
            return res;
        }
        /*release resource*/
        function close()
        {
            mysql_free_result($this->res);
            mysql_close($this->con);
        }
    }
?>