PDO::exec

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

PDO::exec Ejecuta una sentencia SQL y devuelve el número de filas afectadas

Descripción

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

PDO::exec() ejecuta una sentencia SQL en una única llamada a la función, devolviendo el número de filas afectadas por la sentencia.

PDO::exec() no devuelve resultados de una sentencia SELECT. Para una sentencia SELECT que sólo se necesita ejecutar una vez en el programa, se debe considerar el uso de PDO::query(). Para una sentencia que se deba ejecutar en múltiples ocasiones, preparar un objeto PDOStatement con PDO::prepare() y ejecutarlo con PDOStatement::execute().

Parámetros

statement

La sentencia SQL para preparar y ejecutar.

Los datos dentro de la consulta deben ser debidamente escapados.

Valores devueltos

PDO::exec() devuelve el número de filas modificadas o borradas por la sentencia SQL ejecutada. Si no hay filas afectadas, PDO::exec() devuelve 0.

Advertencia

Esta función puede devolver el valor booleano false, pero también puede devolver un valor no booleano que se evalúa como false. Por favor lea la sección sobre Booleanos para más información. Use el operador === para comprobar el valor devuelto por esta función.

El siguiente ejemplo confía incorrectamente en el valor de retorno de PDO::exec(), donde en una sentencia que afecta a 0 filas resulta en una llamada a die():

<?php
$db
->exec() or die(print_r($db->errorInfo(), true));
?>

Ejemplos

Ejemplo #1 Ejecutando una sentencia DELETE

Cuenta el número de filas afectadas por una sentencia DELETE sin cláusula WHERE.

<?php
$dbh
= new PDO('odbc:sample', 'db2inst1', 'ibmdb2');

/* Borra todas las filas de la tabla FRUIT */
$count = $dbh->exec("DELETE FROM fruit WHERE colour = 'red'");

/* Devuelve el número de filas borradas */
print("Deleted $count rows.\n");
?>

El resultado del ejemplo sería:

Deleted 1 rows.

Ver también

  • PDO::prepare() - Prepara una sentencia para su ejecución y devuelve un objeto sentencia
  • PDO::query() - Ejecuta una sentencia SQL, devolviendo un conjunto de resultados como un objeto PDOStatement
  • PDOStatement::execute() - Ejecuta una sentencia preparada

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User Contributed Notes 7 notes

up
38
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.
up
16
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.
up
6
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
up
4
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
up
0
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
}
up
-12
hungry dot rahly at gmail dot com
14 years ago
For those that want an exec that handles params like prepare/execute does.  You can simulate this with another function

<?php
class Real_PDO extends PDO {
  public function
execParams($sql, $params) {
   
$stm = $this->prepare($sql);
   
$result = false;
    if(
$stm && $stm->execute($params) ) {
     
$result = $stm->rowCount();
      while(
$stm->fetch(PDO::FETCH_ASSOC) ) {
      }
    }
    return
$result;
  }
}
?>

Remember though, if you are doing a lot of inserts, you'll want to do it the manual way, as the prepare statement will speed up when doing multiple executes(inserts).  I use this so I can place all my SQL statements in one place, and have auto safe quoting against sql-injections.

If you are wondering about the fetch after, remember some databases can return data SELECT-like data from REMOVE/INSERTS.  In the case of PostgreSQL, you can have it return you all records that were actually removed, or have the insert return the records after the insert/post field functions, and io trigger fire, to give you normalized data.

<?php
define
("BLAH_INSERT", "INSERT INTO blah (id,data) VALUES(?,?)");
$pdo = new Real_PDO("connect string");
$data = array("1", "2");
$pdo->execParams(BLAH_INSERT, $data);
?>
up
-16
blah at whatevr dot com
17 years ago
You can't use it not only with SELECT statement, but any statement that might return rows. "OPTIMIZE table" is such example (returns some rows with optimization status).

If you do, PDO will lock-up with the "Cannot execute queries while other unbuffered queries are active." nonsense.
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