source: trunk/gm_system/database/mysql_database.php@ 638

<?php
/*
  $Id: mysql_database.php 2040 2008-11-23 05:46:25Z andrewsimpson $

  (c) 2002 - 2008 Andrew Simpson <andrew.simpson at paradise.net.nz>

  WebCollab
  ---------------------------------------

  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., 675 Mass Ave,
  Cambridge, MA 02139, USA.

  Function:
  ---------

  Creates a singular interface for mysql database access.

*/

require_once('path.php' );

//set some base variables
$database_connection = '';
$delim = '';
$epoch = 'UNIX_TIMESTAMP( ';
$day_part  = 'DAYOFMONTH( ';
$date_type = '';

//
// connect to database
//
function db_connection() {

  global $database_connection, $db_error_message;

  //make connection
  if( ! ($database_connection = @mysql_connect(DATABASE_HOST, DATABASE_USER, DATABASE_PASSWORD ) ) ) {
    error('No database connection',  'Sorry but there seems to be a problem in connecting to the database server');
  }

  //select database
  if( ! @mysql_select_db(DATABASE_NAME, $database_connection ) ) {
    $db_error_message = mysql_error($database_connection );
    error('Database error', 'Not able to select database tables' );
  }

  //set transaction mode for innodb
  if(DATABASE_TYPE == 'mysql_innodb' ) {
    db_query('SET AUTOCOMMIT = 1' );
  }

  //set timezone
  if(! mysql_query("SET time_zone='".sprintf('%+d:%02d', (int)TZ, (TZ - floor(TZ) )*60 )."'", $database_connection ) ) {
    $db_error_message = mysql_error($database_connection );
    error("Database error", "Not able to set timezone. <br />Check that your version of MySQL is 4.1.3, or higher" );
  }

  return;
}

//
// Provides a safe way to do a query
//
function db_query($query, $die_on_error=1 ) {

  global $database_connection, $db_error_message;

  if(! $database_connection ) db_connection();

  //do it
  if( ! ($result = @mysql_query($query, $database_connection ) ) ) {
    $db_error_message = mysql_error($database_connection );
    if($die_on_error) {
      error('Database query error', 'The following query :<br /><br /><b>'.$query.'</b><br /><br />Had the following error:<br /><b>'.mysql_error($database_connection).'</b>' );
    }
  }

  //all was okay return resultset
  return $result;
}

//
// escapes special characters in a string for use in a SQL statement
//
function db_escape_string($string ) {

  global $database_connection;

  if(! $database_connection ) db_connection();

  return mysql_real_escape_string($string, $database_connection );
}

//
// get single result set
//
function db_result($q, $row=0, $field=0 ) {

  return mysql_result($q, $row, $field );
}

//
// fetch array result set
//
function db_fetch_array($q, $row=0 ) {

 return mysql_fetch_array($q, MYSQL_ASSOC );
}

//
// fetch enumerated array result set
//
function db_fetch_num($q, $row=0 ) {

  return mysql_fetch_row($q );
}

//
// last oid
//
function db_lastoid($seq ) {

  global $database_connection;

  return mysql_insert_id($database_connection );
}

//
//free memory
//
function db_free_result($q ) {

  return mysql_free_result($q );
}

//
//begin transaction
//
function db_begin() {

  global $database_connection;

  //not used for ISAM tables
  if(DATABASE_TYPE == 'mysql' ) return true;

  return mysql_query('BEGIN' );
}

//
//rollback transaction
//
function db_rollback() {

  global $database_connection;

  //not used for ISAM tables
  if(DATABASE_TYPE == 'mysql' ) return true;

  return mysql_query('ROLLBACK' );
}

//
//commit transaction
//
function db_commit() {

  global $database_connection;

  //not used for ISAM tables
  if(DATABASE_TYPE == 'mysql' ) return true;

  return mysql_query('COMMIT' );
}

//
//sets the required session client encoding
//
function db_user_locale($encoding ) {

  global $database_connection, $db_error_message;

  if(! $database_connection ) db_connection();

  switch(strtoupper($encoding ) ) {

    case 'ISO-8859-1':
      $my_encoding = 'latin1';
      break;

    case 'UTF-8':
      $my_encoding = 'utf8';
      break; 

    case 'ISO-8859-2':
      $my_encoding = 'latin2';
      break;

    case 'ISO-8859-7':
      $my_encoding = 'greek';
      break;

    case 'ISO-8859-9':
      //ISO-8859-9 === latin5 in MySQL!!
      $my_encoding = 'latin5';
      break;

     case 'KOI8-R':
      $my_encoding = 'koi8r';
      break;

    case 'WINDOWS-1251':
      $my_encoding = 'cp1251';
      break;

   default:
      $my_encoding = 'latin1';
      break;
  }

  //set character set -- 1
  if(! @mysql_query("SET CHARACTER SET ".$my_encoding, $database_connection ) ) {
    $db_error_message = mysql_error($database_connection );
    error("Database error", "Not able to set CHARACTER SET : ".$my_encoding );
  }

  //set character set -- 2
  if(! @mysql_query("SET NAMES '".$my_encoding."'", $database_connection ) ) {
    $db_error_message = mysql_error($database_connection );
    error("Database error", "Not able to set ".$my_encoding." client encoding" );
  }
  return true;
}

?>