PHP: dbx Functions - Manual

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Last updated: Fri, 26 Jan 2007

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# XXVII. dbx Functions

# Введение

The dbx module is a database abstraction layer (db 'X', where 'X' is a supported database). The dbx functions allow you to access all supported databases using a single calling convention. The dbx-functions themselves do not interface directly to the databases, but interface to the modules that are used to support these databases.

> Замечание: This extension has been moved to the PECL repository and is no longer bundled with PHP as of PHP 5.1.0.

# Требования

To be able to use a database with the dbx-module, the module must be either linked or loaded into PHP, and the database module must be supported by the dbx-module. Currently, the following databases are supported, but others will follow:

- FrontBase (available from PHP 4.1.0).

- Microsoft SQL Server

- MySQL

- ODBC

- PostgreSQL

- Sybase-CT (available from PHP 4.2.0).

- Oracle (oci8) (available from PHP 4.3.0).

- SQLite (PHP 5).

Documentation for adding additional database support to dbx can be found at http://www.guidance.nl/php/dbx/doc/.

# Установка

In order to have these functions available, you must compile PHP with dbx support by using the `--enable-dbx` option and all options for the databases that will be used, e.g. for MySQL you must also specify `--with-mysql=[DIR]`. To get other supported databases to work with the dbx-module refer to their specific documentation.

# Настройка во время выполнения

Поведение этих функций зависит от установок в `php.ini`.

Таблица 1. DBX Configuration Options

Name | Default | Changeable | Changelog
--- | --- | --- | ---
dbx.colnames_case | "unchanged" | PHP_INI_SYSTEM | Available since PHP 4.3.0.

Для подробного описания констант PHP_INI_*, обратитесь к документации функции ini_set().

Краткое разъяснение конфигурационных директив.

`dbx.colnames_case` string

  Columns names can be returned "unchanged" or converted to "uppercase" or "lowercase". This directive can be overridden with a flag to dbx_query().

# Типы ресурсов

There are two resource types used in the dbx module. The first one is the link-object for a database connection, the second a result-object which holds the result of a query.

# Предопределенные константы

Перечисленные ниже константы определены данным расширением и могут быть доступны только в том случае, если PHP был собран с поддержкой этого расширения или же в том случае, если данное расширение подгружается во время выполнения.

`DBX_MYSQL` (integer)

`DBX_ODBC` (integer)

`DBX_PGSQL` (integer)

`DBX_MSSQL` (integer)

`DBX_FBSQL` (integer)

`DBX_OCI8` (integer) (available from PHP 4.3.0)

`DBX_SYBASECT` (integer)

`DBX_SQLITE` (integer) (PHP 5)

`DBX_PERSISTENT` (integer)

`DBX_RESULT_INFO` (integer)

`DBX_RESULT_INDEX` (integer)

`DBX_RESULT_ASSOC` (integer)

`DBX_RESULT_UNBUFFERED` (integer) (PHP 5)

`DBX_COLNAMES_UNCHANGED` (integer) (available from PHP 4.3.0)

`DBX_COLNAMES_UPPERCASE` (integer) (available from PHP 4.3.0)

`DBX_COLNAMES_LOWERCASE` (integer) (available from PHP 4.3.0)

`DBX_CMP_NATIVE` (integer)

`DBX_CMP_TEXT` (integer)

`DBX_CMP_NUMBER` (integer)

`DBX_CMP_ASC` (integer)

`DBX_CMP_DESC` (integer)

add a note User Contributed Notes
dbx Functions
bart at mediawave dot nl
08-Jul-2004 06:45
`Simple function for returning paged result sets.
<?php
// use: pagedQuery($link, $sql, $rows_per_page, $current_page)
function pagedQuery($link, $sql, $nrows = 10, $page = 1) {
$handle = dbx_query($link, $sql, DBX_RESULT_UNBUFFERED);
$result = new stdClass;
$result->link = $this->link;
$result->page = $page;
$result->data = array();
$result->info['name'] = array();
$start = ($page - 1) * $nrows;
$end = $start + $nrows;
$result->rows = 0;
while ($row = dbx_fetch_row($handle)) {
$result->rows++;
if (($result->rows > $start) && ($result->rows <= $end)) {
$result->data[] = $row;
}
}
if ($result->data[0]) {
$result->cols = count($result->data[0]) / 2;
$result->info['name'] = array_slice(array_keys($result->data[0]), $result->cols, $result->cols);
$result->lastPage = ceil($result->rows / $nrows);
}
return $result;
}
?>`
bart at mediawave dot nl
01-Jul-2004 08:12
`Would like to confirm that dbx is at least three times faster than adodb with my application. However, once loaded, adodb has much more features and probably performs better in some situations then dbx.
One of the nice features that adodb has, is the way you can quickly make a dropdown menu from a query. Here's a similar function that works with a dbx result object:
<?php
// $result is the dbx_query result (It expects two fields)
// $name is the name of the dropdown field
// $selected is the option that should be selected
// $firstrow takes a string like "myvalue:myname"
// $attr can be used to add some extra attributes
function dropDown($result, $name, $selected, $firstRow, $attr) {
$s = '<select name="'.$name.'" '.$attr.'>';
if (is_string($firstRow)) {
$row = explode(':', $firstRow);
$s .= '<option value="'.$row[0].'">'.$row[1].'</option>';
} else
$s .= '<option></option>';
foreach ($result->data as $row) {
if ($row[0] == $selected)
$s .= '<option value="'.$row[0].'" selected="selected">'.htmlspecialchars($row[1]).'</option>';
else
$s .= '<option value="'.$row[0].'">'.htmlspecialchars($row[1]).'</option>';
}
return $s.'</select>';
}
?>`
rhcf at linux dot ime dot usp dot br
25-Nov-2003 01:52
`BEWARE!!!
dbx_query allocate all retrieved data in an array on memory. If the query result is big (bigger then the memory_limit on php.ini), the result will be empty. So use dbx wih care.`
carl [at] carlthompson [dot] net
07-Jun-2003 01:49
`The above benchmark is very misleading. Unfortunately, I found out the hard way by porting my app to ADODB. Most PHP apps are going to be very short-lived therefore startup / setup time is a large factor. This benchmark does not measure that. Just include()ing the main ADODB file added 27ms to my app's startup time! Considering my app took only 16ms to run in total using DBX, the idea of switching to ADODB was DOA before running a single query.
In the end, the total time for my app went from 16ms with DBX to 49ms with ADODB. ADODB's powerful features are obviously not worth that kind of overhead.
Carl Thompson`
jlim at natsoft dot com dot my
06-Feb-2003 07:35
`For some benchmarks of dbx connecting to mysql compared to native mysql api, adodb, and others, see:
http://phplens.com/lens/adodb/
http://php.weblogs.com/2003/02/06#a2336`
add a note
dbx_close dbmreplace

Last updated: Fri, 26 Jan 2007
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