PDO::query
(PHP 5 >= 5.1.0, PECL pdo >= 0.2.0)
PDO::query — Executes an SQL statement, returning a result set as a PDOStatement object
Description
$statement
, int $PDO::FETCH_CLASS
, string $classname
, array $ctorargs
)PDO::query() executes an SQL statement in a single function call, returning the result set (if any) returned by the statement as a PDOStatement object.
For a query that you need to issue multiple times, you will realize better performance if you prepare a PDOStatement object using PDO::prepare() and issue the statement with multiple calls to PDOStatement::execute().
If you do not fetch all of the data in a result set before issuing your next call to PDO::query(), your call may fail. Call PDOStatement::closeCursor() to release the database resources associated with the PDOStatement object before issuing your next call to PDO::query().
Note:
Although this function is only documented as having a single parameter, you may pass additional arguments to this function. They will be treated as though you called PDOStatement::setFetchMode() on the resultant statement object.
Parameters
-
statement -
The SQL statement to prepare and execute.
Data inside the query should be properly escaped.
Return Values
PDO::query() returns a PDOStatement object, or FALSE
on failure.
Examples
Example #1 Demonstrate PDO::query
A nice feature of PDO::query() is that it enables you to iterate over the rowset returned by a successfully executed SELECT statement.
<?php
function getFruit($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";
}
}
?>
The above example will output:
apple red 150 banana yellow 250 kiwi brown 75 lemon yellow 25 orange orange 300 pear green 150 watermelon pink 90
See Also
- PDO::exec() - Execute an SQL statement and return the number of affected rows
- PDO::prepare() - Prepares a statement for execution and returns a statement object
- PDOStatement::execute() - Executes a prepared statement
- PHP Руководство
- Функции по категориям
- Индекс функций
- Справочник функций
- Расширения для работы с базами данных
- Уровни абстракции
- Объекты данных PHP
- Функция PDO::beginTransaction() - Инициализация транзакции
- Функция PDO::commit() - Фиксирует транзакцию
- Функция PDO::__construct() - Создает экземпляр PDO, предоставляющий соединение с базой данных
- Функция PDO::errorCode() - Возвращает код SQLSTATE результата последней операции с базой данных
- PDO::errorInfo
- PDO::exec
- Функция PDO::getAttribute() - Получить атрибут соеденения с базой данных
- Функция PDO::getAvailableDrivers() - Возвращает массив доступных драйверов PDO
- Функция PDO::inTransaction() - Проверяет, есть ли внутри транзакция
- Функция PDO::lastInsertId() - Возвращает ID последней вставленной строки или последовательное значение
- PDO::prepare
- PDO::query
- Функция PDO::quote() - Заключает строку в кавычки для использования в запросе
- Функция PDO::rollBack() - Откат транзакции
- Функция PDO::setAttribute() - Присвоение атрибута
Коментарии
> 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);
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);
?>
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;
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);
?>
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");
}
?>
When you make a wraper for PDO:query, you must define the method like this:
public function query( string $sql, ?int $fetchMode = null, mixed ...$fetchModeArgs) : \PDOStatement|false
if you delete one of the parameters or use one of the oficials parameters you get a Fatal error