PDO::exec

(PHP 5 >= 5.1.0, PHP 7, PHP 8, PECL pdo >= 0.1.0)

PDO::exec — Execute an SQL statement and return the number of affected rows

Descrizione

public PDO::exec(string $statement): int|false

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().

Elenco dei parametri

statement

The SQL statement to prepare and execute.

Data inside the query should be properly escaped.

Valori restituiti

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.

Avviso

Questa funzione può restituire il Booleano false, ma può anche restituire un valore non-Booleano valutato come false. Fare riferimento alla sezione Booleans per maggiori informazioni. Usare l'operatore === per controllare il valore restituito da questa funzione.

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
$db->exec() or die(print_r($db->errorInfo(), true)); // incorrect
?>

Errori/Eccezioni

Emits an error with level E_WARNING if the attribute PDO::ATTR_ERRMODE is set to PDO::ERRMODE_WARNING.

Throws a PDOException if the attribute PDO::ATTR_ERRMODE is set to PDO::ERRMODE_EXCEPTION.

Esempi

Example #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");

/* Return number of rows that were deleted */
print "Deleted $count rows.\n";
?>

Il precedente esempio visualizzerà:

Deleted 1 rows.

Vedere anche:

PDO::prepare() - Prepares a statement for execution and returns a statement object
PDO::query() - Prepares and executes an SQL statement without placeholders
PDOStatement::execute() - Executes a prepared statement

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User Contributed Notes 5 notes

down

david at acz dot org ¶

18 years ago

This function cannot be used with any queries that return results. This includes SELECT, OPTIMIZE TABLE, etc.

down

Sbastien ¶

2 years ago

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
}

down

soletan at toxa dot de ¶

18 years ago

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.

down

calin at NOSPAM dot softped dot com ¶

9 years ago

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(): http://php.net/manual/en/pdo.errorinfo.php
List of SQLSTATE Codes: http://www-01.ibm.com/support/knowledgecenter/SSGU8G_11.70.0/com.ibm.sqls.doc/ids_sqs_0809.htm

down

roberto at spadim dot com dot br ¶

18 years ago

this function don't execute multi_query
to get it see SQLITE_EXEC comments there is an pereg function that get all queries and execute all then an return the last one

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