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;
}
?>
dbx Functions
簡介
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.
Note: 本擴充功能已被移動到 » PECL 函式庫中且自以下版本起不再被包含到 PHP 中:5.1.0.
需求
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/.
安裝
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.
執行時期設定
這些函式的行為受 php.ini 的影響。
| Name | Default | Changeable | Changelog |
|---|---|---|---|
| dbx.colnames_case | "unchanged" | PHP_INI_SYSTEM | Available since PHP 4.3.0. Removed in PHP 5.1.0. |
以下是設定選項的簡要解釋。
- 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().
資源類型
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.
預設常數
以下常數由擴充功能定義,因此只有在擴充功能被編譯到 PHP 中,或者在執行時被動態載入後才有效。
- 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)
Table of Contents
- dbx_close — Close an open connection/database
- dbx_compare — Compare two rows for sorting purposes
- dbx_connect — Open a connection/database
- dbx_error — Report the error message of the latest function call in the module
- dbx_escape_string — Escape a string so it can safely be used in an sql-statement
- dbx_fetch_row — Fetches rows from a query-result that had the DBX_RESULT_UNBUFFERED flag set
- dbx_query — Send a query and fetch all results (if any)
- dbx_sort — Sort a result from a dbx_query by a custom sort function
dbx
09-Jul-2004 09:45
02-Jul-2004 11:12
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>';
}
?>
26-Nov-2003 05:52
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.
08-Jun-2003 04:49
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
06-Feb-2003 11:35
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
