PDO::exec
(PHP 5 >= 5.1.0, PECL pdo:0.1-1.0.3)
PDO::exec — Execute an SQL statement and return the number of affected rows
Описание
PDO::exec() executes an SQL statement in a single function call, returning the number of rows affected by the statement.
PDO::exec() does not return results from a SELECT statement. For a SELECT statement that you only need to issue once during your program, consider issuing PDO::query(). For a statement that you need to issue multiple times, prepare a PDOStatement object with PDO::prepare() and issue the statement with PDOStatement::execute().
Список параметров
- statement
-
The SQL statement to prepare and execute.
Возвращаемые значения
PDO::exec() returns the number of rows that were modified or deleted by the SQL statement you issued. If no rows were affected, PDO::exec() returns 0.
Эта функция может возвращать как логическое значение FALSE, так и не относящееся к логическому типу значение, которое приводится к FALSE, например, 0 или "". За более подробной информации обратитесь к разделу Булев тип. Используйте оператор === для проверки значения, возвращаемого этой функцией.
The following example incorrectly relies on the return value of PDO::exec(), wherein a statement that affected 0 rows results in a call to die():
<?php
$db->exec() or die($db->errorInfo());
?>
Примеры
Пример #1 Issuing a DELETE statement
Count the number of rows deleted by a DELETE statement with no WHERE clause.
<?php
$dbh = new PDO('odbc:sample', 'db2inst1', 'ibmdb2');
/* Delete all rows from the FRUIT table */
$count = $dbh->exec("DELETE FROM fruit WHERE colour = 'red'");
/* Return number of rows that were deleted */
print("Deleted $count rows.\n");
?>
Результат выполнения данного примера:
Deleted 1 rows.
- 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
This function cannot be used with any queries that return results. This includes SELECT, OPTIMIZE TABLE, etc.It's worth noting here, that - in addition to the hints given in docs up there - using prepare, bind and execute provides more benefits than multiply querying a statement: performance and security!
If you insert some binary data (e.g. image file) into database using INSERT INTO ... then it may boost performance of parsing your statement since it is kept small (a few bytes, only, while the image may be several MiBytes) and there is no need to escape/quote the file's binary data to become a proper string value.
And, finally and for example, if you want to get a more secure PHP application which isn't affectable by SQL injection attacks you _have to_ consider using prepare/execute on every statement containing data (like INSERTs or SELECTs with WHERE-clauses). Separating the statement code from related data using prepare, bind and execute is best method - fast and secure! You don't even need to escape/quote/format-check any data.
this function don't execute multi_queryto get it see SQLITE_EXEC comments there is an pereg function that get all queries and execute all then an return the last one
PDO::eval() might return `false` for some statements (e.g. CREATE TABLE) even if the operation completed successfully, when using PDO_DBLIB and FreeTDS. So it is not a reliable way of testing the op status.
PDO::errorInfo() can be used to test the SQLSTATE error code for '00000' (success) and '01000' (success with warning).
<?php
function execute(PDO $conn, $sql) {
$affected = $conn->exec($sql);
if ($affected === false) {
$err = $conn->errorInfo();
if ($err[0] === '00000' || $err[0] === '01000') {
return true;
}
}
return $affected;
}
?>
PDO::errorInfo(): pdo.errorinfo
List of SQLSTATE Codes: http://www-01.ibm.com/support/knowledgecenter/SSGU8G_11.70.0/com.ibm.sqls.doc/ids_sqs_0809.htm
Note that with MySQL you can detect a DUPLICATE KEY with INSERT (1 = INSERT, 2 = UPDATE) :
<?php
// MySQL specific INSERT UPDATE-like syntax
$sql = <<<SQL
INSERT INTO customers
SET
id = {$pdo->quote($id)},
name = {$pdo->quote($name)},
address = {$pdo->quote($address)}
AS new
ON DUPLICATE KEY UPDATE
name = new.name,
address = new.address
SQL;
$result = $pdo->exec($sql);
if ($result === 1) {
// An INSERT of a new row has be done
} elseif ($result === 2) {
// An UPDATE of an existing row has be done
}