通過 Pear DB可以從查詢結(jié)果獲得更多有用的數(shù)據(jù)信息 。這些方法有: numRows(): 通過一個(gè)"SELECT" 查詢返回所有數(shù)據(jù)的數(shù)量。
<?php
// UNTESTED CODE !!!
//
// Example inserting data
$alldata = array(
array(1, 'one', 'en'),
array(2, 'two', 'to'),
array(3, 'three', 'tre'),
array(4, 'four', 'fire')
);
$sth = $dbh->prepare("INSERT INTO numbers VALUES( , , )");
foreach ($alldata as $row) {
$dbh->execute($sth, $row);
}
//Here's an example of a file placeholder:
$myfile = "/tmp/image.jpg";
$sth = $dbh->prepare('INSERT INTO images ( , &)');
$dbh->execute($sth, array("this is me", $myfile));
//After I commit a bugfix that I have on my laptop, you can use
//parameter arrays in the getXxx methods too:
$ver = $dbh->getOne("SELECT stableversion FROM packages WHERE name = ",
array($package));
?>
|
3.8 autoCommit, commit and rollback
4. 可用方法列表
<?php
/*
* From the DB_(driver) objects
*/
// get the object with, ie:
$db = DB::connect('mysql://user:pass@localhost/my_db');
// Set options
$db->setErrorHandling();
$db->setFetchmode();
// Information
$db->affectedRows();
$db->tableInfo();
// Database manipulation
$db->query();
// Data fetch
$db->nextId();
$db->getOne();
$db->getRow();
$db->getCol();
$db->getAssoc();
$db->getAll();
// Place holders and execute related
$db->quote();
$db->prepare();
$db->execute();
$db->executeMultiple();
// Transactions
$db->autoCommit();
$db->commit();
$db->rollback();
// Disconnection
$db->disconnect();
/*
* From DB_result objects
*/
// get the object with, ie:
$res = $db->query('select * from foo');
// Data fetch
$res->fetchRow();
$res->fetchInto();
// Result Info
$res->numCols();
$res->numRows();
$res->tableInfo();
// Free
$res->free();
/*
* From DB_error objects
*/
// get the object with, ie:
$error = $db->query('select * from no_table');
$error->getMessage();
$error->getDebugInfo();
$error->toString();
?>
|
5. 錯(cuò)誤處理機(jī)制
5.1. 從Pear DB Error獲得錯(cuò)誤信息
所有從Pear DB 返回的錯(cuò)誤都是Pear Errors. 這有一種方法來搜集:
<?php
...
$res = $db->query('select * from no_table');
if (DB::isError($res)) {
// get the portable error string
echo $res->getMessage();
}
?>
|
4.2 Debug Pear DB Errors
Pear DB采用一種輕便的錯(cuò)誤消息系統(tǒng)向用戶報(bào)錯(cuò)。把錯(cuò)誤信息簡單翻譯成其它語言或者對于一種特殊錯(cuò)誤采取特殊的處理方式這都帶來了很大的優(yōu)點(diǎn)。但是對于開發(fā)人員來說這些提示并么有提供很有用的信息。想要得到真實(shí)的數(shù)據(jù)處理出錯(cuò)的信息，你可以使用getDebugInfo()方法:
<?php
$sql = 'select * from no_table';
if (DB::isError($res = $db->query($sql))) {
// get the native backend error
// and the last query
echo $res->getDebugInfo();
}
?>
|
通過當(dāng)一個(gè)PHP函數(shù)出錯(cuò)時(shí)，會(huì)打印出出錯(cuò)提示。在pear中的這種機(jī)制被屏蔽了。但時(shí)有時(shí)你可能需要在代碼中捕捉一些錯(cuò)誤信息?？梢允褂?/FONT>set_error_handler PHP 函數(shù), 從 PHP Manual獲取信息.簡單示例:
<?php
// what messages to report
error_reporting (E_ALL ^ E_NOTICE);
// this function will handle all reported errors
function my_error_handler ($errno, $errstr, $errfile, $errline) {
echo "In $errfile, line: $errline\n
$errstr";
}
set_error_handler ('my_error_handler');
$db = DB::connect('pgsql://postgres@localhost/no_db');
...
?>
|
5.3 對錯(cuò)誤采取自動(dòng)處理
正如你所看見的， Pear DB提供了廣泛的錯(cuò)誤檢測和報(bào)告機(jī)制，這強(qiáng)迫開發(fā)人員必需對返回的數(shù)據(jù)結(jié)果進(jìn)行檢查，是否有錯(cuò)。 Pear DB同時(shí)照顧我們避免這種痛苦的工作，提供了一種靈活的體系，在一個(gè)錯(cuò)誤出現(xiàn)的時(shí)候自動(dòng)調(diào)用相應(yīng)的措施。
這些可能的措施包括:
- 返回錯(cuò)誤對象 (PEAR_ERROR_RETURN). 這是默認(rèn)的.
- 打印錯(cuò)誤 (PEAR_ERROR_PRINT)
- 打印錯(cuò)誤信息并忽略執(zhí)行(PEAR_ERROR_DIE)
- 用PHP函數(shù) trigger_error()來列舉錯(cuò)誤(PEAR_ERROR_TRIGGER)
- 把錯(cuò)誤對象傳遞給一個(gè)函數(shù)或者類的方法 (PEAR_ERROR_CALLBACK)
簡單示例:
<?php
require_once 'DB.php';
// Set the default action to take on error
PEAR::setErrorHandling(PEAR_ERROR_DIE);
// From here you don't need to check errors any more
$db = DB::connect('pgsql://postgres@localhost/my_database');
$res = $db->query('select id from no_table');
// at this point the execution is aborted and the error message is raisen
...
?>
|
高級示例:
<?php
// Define the app environment (this is: what errors you want to output)
define ('DEBUG_ENV', true);
// This function will handle all errors
function handle_pear_error ($error_obj) {
// Be verbose while developing the application
if (DEBUG_ENV) {
die ($error_obj->getMessage()."\n".$error_obj->getDebugInfo());
// Dump a silly message if the site is in production
} else {
die ('Sorry you request can not be processed now. Try again later');
}
}
require_once 'DB.php';
// On error, call the "handle_pear_error" function back
// You can also use an object as pear error handler so:
// setErrorHandling(PEAR_ERROR_CALLBACK, array($object,'method_name');
PEAR::setErrorHandling(PEAR_ERROR_CALLBACK, 'handle_pear_error');
$db = DB::connect('pgsql://postgres@localhost/site_db');
$res = $db->query('select id from no_table');
// at this point the execution is aborted and the "handle_pear_error"
// function is called with the error object as its first argument
while ($row = $res->fetchRow()) {
...
}
...
?>
|
下面為擴(kuò)展錯(cuò)誤機(jī)制提供了一個(gè)很好的想法：
<?php
error_reporting (E_ALL ^ E_NOTICE);
// this function will handle all errors reported by PHP
function php_error_handler ($errno, $errstr, $errfile, $errline) {
die ("In $errfile, line: $errline\n
$errstr");
}
set_error_handler ('php_error_handler');
// this function will catch errors generated by Pear,
// transform it to PHP errors and trigger them to the php_error_handler
function pear_error_handler ($err_obj) {
$error_string = $err_obj->getMessage() . '
' . $error_obj->getDebugInfo();
trigger_error ($error_string, E_USER_ERROR);
}
require 'DB.php';
PEAR::setErrorHandling (PEAR_ERROR_CALLBACK, 'pear_error_handler');
// force an error
$db = DB::connect('pgsql://postgres@localhost/no_db');
...
?>
|
mysql 字段類型說明...2007-04-04
這篇文章主要為大家介紹了PHP定界符php和html代碼混編方法實(shí)例詳解,有需要的朋友可以借鑒參考下,希望能夠有所幫助,祝大家多多進(jìn)步,早日升職加薪2024-01-01
base64+gzinflate壓縮編碼（加密）過的文件通常是以 <? eval(gzinflate(base64_decode( 為頭的一個(gè)php文件。文中給出了編碼和解碼的代碼。2008-10-10