Model.class.php

include 'config.php';

class Model{

    //用户名

    protected $user;

    //密码

    protected $pwd;

    //主机

    protected $host;

    //库名，是一个数组

    protected $dbName=array();

    //字符集

    protected $charset='utf8';

    //连接资源是一个数组

    protected $_link=array();

    //通用表名

    protected $tabName;

    //真实表名

    protected $trueTabName;

    //表前缀

    protected $prefix;

    //字段缓存

    protected $fields;

    //创建表的sql语句

    protected $createSql='CREATE TABLE IF NOT EXISTS __TABLENAME__(

  `id` mediumint(9) NOT NULL AUTO_INCREMENT,

  `username` char(15) NOT NULL,

  `password` char(32) NOT NULL,

  `createtime` int(11) NOT NULL,

  PRIMARY KEY (`id`)

) ENGINE=MyISAM  DEFAULT CHARSET=utf8 AUTO_INCREMENT=1;';

//1,通过ID取余，得到真实表名    mod

//2,用户名截取前几位   substr

//3,md5            md5

//4,不带分库分表        none

    protected $partition=array(

        'type'=>'md5',   

        'rule'=>1,

    );

    public function __construct($tabName=''){

        $this->user=DB_USER;

        $this->host=DB_HOST;

        $this->dbName[0]=DB_NAME;

        $this->charset=DB_CHARSET;

        $this->prefix=DB_PREFIX;

        $this->pwd=DB_PWD;

        if(empty($tabName)){

        //userModel

        //newModel

            $this->tabName=$this->prefix.ucfirst(strtolower(substr(get_class($this),0,-5)));

        }else{

            $this->tabName=$this->prefix.$tabName;

        }

        $this->_link[0]=$this->connect($this->host,$this->user,$this->pwd,$this->dbName,$this->charset);

    }

    public function connect($host,$user,$pwd,$dbName,$charset,$linkId=0){

        $conn=mysql_connect($host,$user,$pwd);

        if(mysql_errno()){

            $this->error(-1,$conn);

            return false;

        }

        if(!$this->selectDb($dbName[$linkId],$conn)){

            $this->error(-2,$conn);

            return false;   

        }

        if(!$this->setCharset($charset,$conn)){

            $this->error(-3,$conn);

            return false;

        }

        return $conn;

    }

    public function selectDb($dbName,$conn){

        if(mysql_select_db($dbName,$conn)){

            return true;

        }else{

            return false;

        }   

    }

    public function setCharset($charset,$conn){

        if(mysql_set_charset($charset,$conn)){

            return true;

        }else{

            return false;

        }

    }

    public function addServer($host,$user,$pwd,$dbName,$charset,$linkId){

        $this->dbName[$linkId]=$dbName;

        $this->_link[$linkId]=$this->connect($host,$user,$pwd,$dbName,$charset,$linkId);

    }

    public function getTrueTable($content,$linkId=0){

        switch($this->partition['type']){

            case 'mod':

                if(!is_int($content)){

                    $this->error(-4);

                    return false;

                }

                $string=$content%$this->partition['rule'];

                break;

            case 'substr':

                $string=substr($content,0,$this->partition['rule']);

                break;

            case 'md5':

                $string=substr(md5($content),0,$this->partition['rule']);

                break;

            case 'none':

                $string=null;

                break;

        }

        if(empty($string)){

            $this->trueTableName=$this->tabName;

        }else{

            $this->trueTableName=$this->tabName.'_'.$string;

        }

        //第一，判断表是否存在，存在返回表字段缓存

        //第二，不存在，则创建表，返回字段缓存

            $this->existsTable($this->trueTableName,$linkId);

    }

    //表是否存在

    //是否缓存了字段

    protected function existsTable($tableName,$linkId=0){

        $database=$this->dbName[$linkId];

        $sql='select `TABLE_NAME` from `INFORMATION_SCHEMA`.`TABLES` where `TABLE_SCHEMA`=\''.$database.'\' and `TABLE_NAME`=\''.$tableName.'\'';

        if($this->execute($sql,$linkId)){

            //表存在

            if(file_exists('cache/'.md5($this->tabName).'.php')){

                $this->fields=include 'cache/'.md5($this->tabName).'.php';

            }else{

                //暂时留着不写，待会来写

                $this->fields=$this->getFieldCache($linkId);

            }

        }else{

            //表不存在

            $this->createTable($this->trueTableName,$linkId);

            $this->fields=$this->getFieldCache($linkId);

        }

    }

    protected function getFieldCache($linkId=0){

        if(file_exists('cache/'.md5($this->tabName).'.php')){

            $fields=include 'cache/'.md5($this->tabName).'.php';

            return $fields;   

        }

        $sql="desc $this->trueTableName";

        $f=$this->query($sql,$linkId);

        $fields=$this->writeFields($f);

        return $fields;

    }

    protected function writeFields($f){

        foreach($f as $key=>$value){

            $fields[]=$value['Field'];

            if($value['Key']=='PRI'){

                $fields['_pk']=$value['Field'];

            }

            if($value['Extra']=='auto_increment'){

                $fields['_auto']=$value['Field'];

            }

        }

        $string="";

        file_put_contents('cache/'.md5($this->tabName).'.php',$string);

        return $fields;

    }

    protected function createTable($tabName,$linkId=0){

        $sql=str_replace('__TABLENAME__',$tabName,$this->createSql);

        $this->execute($sql,$linkId);

    }

    //不需要返回结果集我用execute方法

    public function  execute($sql,$linkId=0){

        $conn=$this->_link[$linkId];

        $result=mysql_query($sql,$this->_link[$linkId]);

        if($result&&mysql_affected_rows()){

            return mysql_affected_rows();

        }else{

            return false;

        }

    }

    //需要返回结果集我用query方法

    public function query($sql,$linkId=0){

        $result=mysql_query($sql,$this->_link[$linkId]);

        if($result&&mysql_affected_rows()){

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

                $rows[]=$row;

            }

        }else{

            return false;

        }

        return $rows;

    }

    public function error($num,$conn){

        switch($num){

            case -1:

                $string='连接数据库服务器失败'.mysql_error($conn);

                break;

            case -2:

                $string='选择数据失败';

                break;

            case -3:

                $string='设置字符集失败';

                break;

            case -4:

                $string='数据库路由时选择的是取余，传入的不是整型';

                break;

        }

    }

    //查最大值

    public function max($field,$linkId=0){

        if(!in_array($field,$this->fields)){

            return false;

        }

        $sql="select max($field) as re from $this->trueTableName";

        $result=$this->query($sql,$linkId);

        $row=$result['re'];

        return $row;

    }   

    //查最小值

    public function min($field,$linkId=0){

        if(!in_array($field,$this->fields)){

            return false;

        }

        $sql="select min($field) as re from $this->trueTableName";

        $result=$this->query($sql,$linkId);

        $row=$result['re'];

        return $row;

    }

    //求和

    public function sum($field,$linkId=0){

        if(!in_array($field,$this->fields)){

            return false;

        }

        $sql="select sum($field) as re from $this->trueTableName";

        $result=$this->query($sql,$linkId);

        $row=$result['re'];

        return $row;

    }

    //最平均数

    public function avg($field,$linkId=0){

        if(!in_array($field,$this->fields)){

            return false;

        }

        $sql="select avg($field) as re from $this->trueTableName";

        $result=$this->query($sql,$linkId);

        $row=$result['re'];

        return $row;

    }

    //求总数

    public function count($field='',$linkId=0){

        if(empty($field)){

            $field=$this->fields['_pk'];

        }

        $sql="select count($field) as re from $this->trueTableName";

        $result=$this->query($sql,$linkId);

        $row=$result['re'];

        return $row;

    }

    //

    //删除

    public function delete($data,$where='',$linkId=0,$order='',$limit=''){

        //delete from 表  where 字段  order by  字段 limit

        if(is_array($data)){

            $value=join(',',$data);

        }else{

            $value=(int)$data;

        }

        $fields=$this->fields['_pk'];

        if(empty($where)){

            $sql="delete from $this->trueTableName where $fields in ($value)";

        }else{

            $where='where '.$where;

            if(!empty($order)){

                $order='order by '.$order;   

            }

            if(!empty($limit)){

                $limit='limit '.$limit;   

            }

            $sql="delete from $this->trueTableName $where $order $limit";

        }

        return $this->execute($sql,$linkId);

    }

    //

    //修改

    public function save($data,$where,$linkId=0,$order='',$limit=''){

        //update 表  set 字段=值,字段=值 where 条件 order  limit

        $key=array_keys($data);

        $newKey=array_intersect($key,$this->fields);

        foreach($data as $key=>$value){

            if(!in_array($key,$newKey))

                continue;

            $update.=$key.'="'.$value.'",';

        }

        $update=rtrim($update,',');

        if(!empty($order)){

            $order='order by '.$order;

        }

        if(!empty($limit)){

            $limit='limit '.$limit;

        }

        if(!empty($where)){

            $where='where '.$where;

        }

        $sql="update $this->trueTableName set $update $where $order $limit";

        echo $sql;

        $result=$this->execute($sql,$linkId);

        return $result;

    }

    //增加

    public function add($data,$linkId=0){

        //insert into 表(字段) values(值)

        $key=array_keys($data);

        $newKey=array_intersect($key,$this->fields);

        foreach($data as $key=>$value){

            if(!in_array($key,$newKey))

                continue;

            $values.="'".$value."',";

        }

        $values=trim($values,',');

        $fields=join(',',$newKey);

        $sql="insert into $this->trueTableName($fields) values($values)";

        echo $sql;

        $result=$this->execute($sql,$linkId);

        return $result;

    }

    //单条查询

    public function find($linkId=0,$where='',$order=''){

        //select * from 表 where  order  limit 1

        $field=join(',',$this->fields);

        if(!empty($where)){

            $where='where '.$where;

        }

        if(!empty($order)){

            $order='order by '.$order;

        }

        $sql="select $field from $this->trueTableName $where $order limit 1";

        $result=$this->query($sql,$linkId);

        return $result[0];

    }

    //多条查询

    public function select($field='',$linkId=0,$where='',$order='',$limit=''){

        //select * from 表 where  order  limit

        if(empty($field)){

            $fields=join(',',$this->fields);

        }else{

            if(is_array($field)){

                $newKey=array_intersect($field,$this->fields);

                $fields=implode(',',$newKey);

            }else{

                $fields=$field;

            }

        }

        if(!empty($where)){

            $where='where '.$where;

        }

        if(!empty($order)){

            $order='order by '.$order;

        }

        if(!empty($limit)){

            $limit='limit '.$limit;

        }

        $sql="select $fields from $this->trueTableName $where $order $limit";

        $result=$this->query($sql,$linkId);

        return $result;

    }

    //按照字段来查询数据

    function __call($name,$param){

        $key=substr($name,0,5);

        if(strtolower($key)=='getby'){

            $field=strtolower(substr($name,5));

            if(!in_array($field,$this->fields)){

                return false;

            }

            $f=join(',',$this->fields);

            $value=$param[0];

            $sql="select $f  from $this->trueTableName where $field='$value'";

            $result=$this->query($sql);

            return $result[0];

        }

    }