php 实现 ruby on rails active recorder

<?php

define('FIND_PARTTERN','/^find_(.+)(_and_.+)*(_by_)?(.+)?(_and_.+)*(_or_.+)*$/');
define('UPDATE_PARTTERN','/^update_(.+)(_and_.+)*(_by_)?(.+)?(_and_.+)*(_or_.+)*$/');
define('DELETE_PARTTERN','/^delete_by_(.+)(_and_.+)*(_or_.+)*$/');
define('SQL_CACHE','../_/_____.php');


include('../configs/config.php');
include(SQL_CACHE);

function get_key_words()
{
    return array('all'=>'*','_or_'=>'or','_by_'=>'where','find_'=>'select','_and_'=>'and','delete'=>'delete','update_'=>'update');
}

function get_key_part_words()
{
    return array('_or','_by','fin','_an','upd','del','find','_and','upda','dele','updat','delet','update');
}

class DB
{
    private $conn=null;
    private $conn_state=null;
    
    public function open()
    {
        $all_db_conf = get_all_db_conf();
        $conf = $all_db_conf[get_class($this)];
        $this->conn = mysql_connect($conf[0],$conf[1],$conf[2]);
        $names=$this->get_names();
        mysql_query("SET NAMES $names", $this->conn);
        mysql_select_db($conf[3]);
        $this->conn_state='opened';
    }

    public function get_names()
    {
        return 'utf8';
    }
    
    public function query_rows($sqls)
    {
        if($this->conn_state!='opened')
        {
            $this->open();
            $auto_close=true;
        }
        
        $array=array();
        $result = mysql_query($sqls,$this->conn);
        while($row = mysql_fetch_assoc($result))
        {
            $array[] = $row;
        }
        
        mysql_free_result($result);
        
        if($auto_close)
            $this->close();
        
        return $array;
    }
    
    public function execute_non_query($sqls)
    {
        if($this->conn_state!='opened')
        {
            $this->open();
            $auto_close=true;
        }
        
        $result = mysql_query($sqls);
        if($auto_close)
            $this->close();
            
        return $result;
    }
    
    public function close()
    {
        mysql_close($this->conn);
        $this->conn_state='closed';
    }  
}

abstract class Table
{
    private $table_name = null;
    private $db = null;
    
    public function __construct()
    {
        $this->table_name = get_class($this);
        $this->db = $this->get_db();
    }
    
    protected abstract function get_db();
    
    public function query_rows($sqls)
    {
        return $this->db->query_rows($sqls);
    }
    
    public function execute_non_query($sqls)
    {
        return $this->db->execute_non_query($sqls);    
    }
    
    public function append($single_row_to_append)
    {
        $sqls = "insert into $this->table_name ( ";
        $values = '( ';
        $has_item = false;
        
        foreach($single_row as $k => $v)
        {
            if($has_item)
            {
                $sqls.=',';
                $values.=',';
            }
            
            $sqls.=$k;
            $values.="'$v'";
            $has_item = true;
        }
        
        return $this->db->execute_non_query("$sqls ) values $values )");
    }
    
    public function delete_by_condition($condition)
    {
        return $this->db->execute_non_query("delete from $this->table_name where $condition");
    }
    
    public function find_all()
    {
        return $this->db->query_rows("select * from $this->table_name");
    }
    
    public function find_all_by_condition($condition)
    {
        return $this->db->query_rows("select * from $this->table_name where $condition");
    }

    public function __call($name,$arguments)
    {
        $v = get_class($this->get_db()).'_'.$this->table_name.'_'.$name;

        global $$v;
        $u = $$v;

        if(isset($u))
        {
            return $this->execute_query_or_non(vsprintf($u,$arguments));
        }


        $sqls = $this->parse_sql_from_name($name,$arguments);

        if($sqls=='syntax error')
        {
            echo $sqls;
            return;
        }

        $this->write_parsed_sqls("\$$v=\"$sqls\";");

        return $this->execute_query_or_non(vsprintf($sqls,$arguments));
    }

    //////////////////////////////////////////////////////////////////

    private function write_parsed_sqls($message)
    {
        $fp=fopen(SQL_CACHE,'a');
        fwrite($fp,"<?php $message ?>\r\n");
        fclose($fp);
    }

    private function parse_sql_from_name($name,$arguments)
    {
        $key_words= get_key_words();
        $key_part_words= get_key_part_words();
        $length = strlen($name);
        $s='';
        $tokens=array();
        $verb='';
        
        if(preg_match(UPDATE_PARTTERN,$name))
            $verb='update';
        else if(preg_match(FIND_PARTTERN,$name))
            $verb = 'select';
        else if(preg_match(DELETE_PARTTERN,$name))
            $verb = 'delete';
        else
            return 'syntax error';
        
        $after_where = false;
        
        for($i=0;$i<$length;)
        {
            for($j=3;$j<=7;$j++)
            {
                $token = substr($name,$i,$j);
                if(array_key_exists($token,$key_words))
                {
                    if($s!='')
                    {
                        if($after_where && $s!='condition')
                            $tokens[]="$s='%s'";
                        else if($s=='condition')
                                $tokens[]='%s';
                        else
                        {
                            if($verb=='update')
                                $tokens[]="$s='%s'";
                            else
                                $tokens[]=$s;
                        }
                        
                        $s='';
                    }
                    
                    if($token=='_by_')
                        $after_where = true;
                    
                    if(!$after_where && $token=='_and_')
                        $tokens[]=',';
                    else
                        $tokens[]=$key_words[$token];
                    
                    $i+=$j;
                    
                    break;
                }
                else if(in_array($token,$key_part_words))
                {
                    continue;
                }
                else
                {
                    $s.= $name[$i];
                    $i++;
                    break;
                }
            }
        }
        
        if($s!='')
        {
            if($s=='condition')
                $tokens[]='%s';
            else if($after_where && $s!='condition')
                    $tokens[]="$s='%s'";
            else
            {
                if($verb=='update')
                    $tokens[]="$s='%s'";
                else
                    $tokens[]=$s;
            }
        }
        
        switch($verb)
        {
            case 'select':
                $where_index = array_search('where',$tokens);
                if($where_index)
                    $tokens[$where_index] = "from $this->table_name where";
                else
                    $tokens[] = "from $this->table_name";
                return implode(' ',$tokens);

            case 'update':
                $tokens[0]="update $this->table_name set";
                return implode(' ',$tokens);
                
            case 'delete':
                $tokens[0]="delete from $this->table_name";
                return implode(' ',$tokens);

        }    
    }
    
    private function execute_query_or_non($sqls)
    {
        echo $sqls;

        if(substr($sqls,0,6)=='select')
            return $this->db->query_rows($sqls);
        else
            return $this->db->execute_non_query($sqls);
    }
}

?>