The handling of errors by this function is controlled by the attribute PDO::ATTR_ERRMODE.
Use the following to make it throw an exception:
<?php
$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
?>
PHP - Manual: PDO::query
2024-11-15
(PHP 5 >= 5.1.0, PHP 7, PHP 8, PECL pdo >= 0.2.0)
PDO::query — 执行 SQL 语句,以 PDOStatement 对象形式返回结果集
$statement
,$PDO::FETCH_CLASS
,$classname
,$ctorargs
PDO::query() 在单次函数调用内执行 SQL 语句,以 PDOStatement 对象形式返回结果集(如果有数据的话)。
如果反复调用同一个查询,用 PDO::prepare() 准备 PDOStatement 对象,并用 PDOStatement::execute() 执行语句,将具有更好的性能。
如果没有完整获取结果集内的数据,就调用下一个 PDO::query(),将可能调用失败。 应当在执行下一个 PDO::query() 前,先用 PDOStatement::closeCursor() 释放数据库PDOStatement 关联的资源。
注意:
如果传入函数的参数数量超过一个,多余的参数将相当于调用结果对象 PDOStatement::setFetchMode() 方法。
PDO::query() 返回 PDOStatement 对象,或在失败时返回 false
。
示例 #1 展示 PDO::query 的使用
PDO::query() 一个不错的功能是:执行 SELECT 语句,并能够循环遍历结果集。
<?php
function getFruit($conn) {
$sql = 'SELECT name, color, calories FROM fruit ORDER BY name';
foreach ($conn->query($sql) as $row) {
print $row['name'] . "\t";
print $row['color'] . "\t";
print $row['calories'] . "\n";
}
}
?>
以上例程会输出:
apple red 150 banana yellow 250 kiwi brown 75 lemon yellow 25 orange orange 300 pear green 150 watermelon pink 90
The handling of errors by this function is controlled by the attribute PDO::ATTR_ERRMODE.
Use the following to make it throw an exception:
<?php
$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
?>
Trying to pass like second argument PDO::FETCH_ASSOC it still work.
So passing FETCH TYPE like argument seems work.
This save you from something like:
<?php
$result = $stmt->setFetchMode(PDO::FETCH_NUM);
?>
Example:
<?php
$res = $db->query('SELECT * FROM `mytable` WHERE true', PDO::FETCH_ASSOC);
?>
> When query() fails, the boolean false is returned.
I think that is "Silent Mode".
If that set attribute ErrorMode "Exception Mode"
then that throw PDOException.
$pdoObj = new PDO( $dsn, $user, $pass );
$pdoObj->setAttribute("PDO::ATTR_ERRMODE", PDO::ERRMODE_EXCEPTION);
After a lot of hours working with DataLink on Oracle->MySQL and PDO we (me and Adriano Rodrigues, that solve it) discover that PDO (and oci too) need the attribute AUTOCOMMIT set to FALSE to work correctly with.
There's 3 ways to set autocommit to false: On constructor, setting the atribute after construct and before query data or initiating a Transaction (that turns off autocommit mode)
The examples:
<?php
// First way - On PDO Constructor
$options = array(PDO::ATTR_AUTOCOMMIT=>FALSE);
$pdo = new PDO($dsn,$user,$pass,$options);
// now we are ready to query DataLinks
?>
<?php
// Second Way - Before create statements
$pdo = new PDO($dsn,$user,$pass);
$pdo->setAttribute(PDO::ATTR_AUTOCOMMIT,FALSE);
// or
$pdo->beginTransaction();
// now we are ready to query DataLinks
?>
To use DataLinks on oci just use OCI_DEFAULT on oci_execute() function;
I would like to mention fetching rows from SQL query using PDO:
<?php
$dbh = new PDO('mysql:host=localhost;dbname=test', $user, $pass);
// use the connection here
$sth = $dbh->query('SELECT * FROM countries');
// fetch all rows into array, by default PDO::FETCH_BOTH is used
$rows = $stm->fetchAll();
// iterate over array by index and by name
foreach($rows as $row) {
printf("$row[0] $row[1] $row[2]\n");
printf("$row['id'] $row['name'] $row['population']\n");
}
?>