Скрипты для WEB - PHP Java Perl

Скрипт представляет собой набор двух классов PHP, которые совместно формируют абстрактный интерфейс для всех существующих баз данных, поддерживающих стандарт PHP.Имеется множество баз данных, которые поддерживают этот стандарт, но к сожалению не существует единственного понятного интерфейса для всех, а для каждой базы данных имеется собственный набор функций. Данный скрипт исправляет в некотором роде сложившуюся ситуацию, используя эту программу Вы сможете использовать функциональные возможности любой базы данных, при этом Ваши приложения будут восприимчивы к разнообразию свойств и функций различных баз данных.

<?php
/*****************************************************************************

  Abstract DB , MySQL module, version 2.0b3

  Copyright (C) 1998  Muze

  This program is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public License
  as published by the Free Software Foundation; either version 2
  of the License, or (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*****************************************************************************

  for information,comments or bugreports, mail abstractdb@muze.nl

  Changelog:

  v2.0 mar. 2000
    - added query->fieldname()

  v2.0b3 22 jan. 1998
    - db->db() constructor now sets a type variable (db->type) with the
      default value of 'database_type'.
    - new function query->error() which returns a description of the last
      mysql error.
    - changed db->nextid() to use autoincrement capabilities of mysql, code
      contributed by Brian Moon.
    - added check $this->result!=0 in query->getrow
    - added @ on mysql_data_seek in query->firstrow

  v2.0b2 1 dec. 1998
    - fixed 2 small bugs in db->nextid() when db_sequence doesn't exist yet.

  v2.0b1 first version with the new interface. 
 
*****************************************************************************/

class db {

  var $connect_id;
  var $type;

  function db($database_type="mysql") {
    $this->type="mysql";
    // dl("mysql");
  }

  function open($database="{database}", $host="{host}", $user="{user}", $password="{password}") {
    $this->connect_id=mysql_pconnect($host, $user, $password);
    if ($this->connect_id) {
      $result=mysql_select_db($database);
      if (!$result) {
        mysql_close($this->connect_id);
        $this->connect_id=$result;
      }
    }
    return $this->connect_id;
  }

  function lock($table, $mode="write") {
  // mode maybe 'read' or 'write'

    $query=new query($this, "lock tables $table $mode");
    $result=$query->result;
    return $result;
  }

  function unlock() {
  // unlocks any and all tables which this process locked

    $query=new query($this, "unlock tables");
    $result=$query->result;
    return $result;
  }

  function nextid($sequence) {
  // Function returns the next available id for $sequence, if it's not
  // already defined, the first id will start at 1.
  // This function will create a table for each sequence called
  // '{sequence_name}_seq' in the current database.
  // Based on code by Brian Moon.

    $esequence=ereg_replace("'","''",$sequence)."_seq";
    $query=new query($this, "REPLACE INTO $esequence values ('', nextval+1)");
    if ($query->result) {
      $nextid=mysql_insert_id($this->connect_id);
    } else {
      $query->query($this, "CREATE TABLE $esequence ( seq char(1)
DEFAULT '' NOT NULL, nextval bigint(20) unsigned DEFAULT '0' NOT NULL auto_increment,
PRIMARY KEY (seq), KEY nextval (nextval) )");
      // there's no way to check if a create table has succeeded except by trying to insert
      // a new value. Since you don't want an endless loop, a recursive call to
      // nextid should not be made:
      $query->query($this, "REPLACE INTO $esequence VALUES ( '', nextval+1 )");
      if ($query->result) {
        $nextid=mysql_insert_id($this->connect_id);
      } else {
        $nextid=0;
      }
    }
    return $nextid;
  }          

  function error() {
    return mysql_errno($this->connect_id).": ".mysql_error($this->connect_id);
  }
    
  function close() {
  // Closes the database connection and frees any query results left.

    if ($this->query_id && is_array($this->query_id)) {
      while (list($key,$val)=each($this->query_id)) {
        @mysql_free_result($val);
      }
    }
    $result=@mysql_close($this->connect_id);
    return $result;
  }

  function addquery($query_id) {
  // Function used by the constructor of query. Notifies the
  // this object of the existance of a query_result for later cleanup
  // internal function, don't use it yourself.

    $this->query_id[]=$query_id;
  }
 
};

/************************************** QUERY ***************************/

class query {

  var $result;
  var $row;

  function query(&$db, $query="") {
  // Constructor of the query object.
  // executes the query, notifies the db object of the query result to clean
  // up later

    if ($query) {
      if ($this->result) {
        $this->free(); // query not called as constructor therefore there may
                       // be something to clean up.
      }
      $this->result=mysql_query($query, $db->connect_id);
      $db->addquery($this->result);
    }
  }
 
  function getrow() {
  // Gets the next row for processing with $this->field function later.

    if ($this->result) {
      $this->row=mysql_fetch_array($this->result);
    } else {
      $this->row=0;
    }
    return $this->row;
  }
  
  function field($field) {
  // get the value of the field with name $field
  // in the current row

    $result=$this->row[$field];
    return $result;
  }

  function fieldname($fieldnum) {
  // return the name of field number $fieldnum
  // only call this after query->getrow() has been called at least once

    return mysql_field_name( $this->result, $fieldnum );
  }

  function firstrow() {
  // return the current row pointer to the first row
  // (CAUTION: other versions may execute the query again!! (e.g. for oracle))
 
    $result=@mysql_data_seek($this->result,0);
    if ($result) {
      $result=$this->getrow();
    }
    return $this->row;
  }

  function free() {
  // free the mysql result tables

    return @mysql_free_result($this->result);
  }

};

?>