PDO::prepare

(no version information, might be only in CVS)

PDO::prepare --  Prepares a statement for execution and returns a statement object

Descrizione

PDOStatement PDO::prepare ( string statement [, array driver_options] )

Avvertimento

Questa funzione è SPERIMENTALE. Ovvero, il comportamento di questa funzione, il nome di questa funzione, in definitiva tutto ciò che è documentato qui può cambiare nei futuri rilasci del PHP senza preavviso. Siete avvisati, l'uso di questa funzione è a vostro rischio.

Prepares an SQL statement to be executed by the PDOStatement::execute() method. The SQL statement can contain zero or more named (:name) or question mark (?) parameter markers for which real values will be substituted when the statement is executed.

Calling PDO::prepare() and PDOStatement::execute() for statements that will be issued multiple times with different parameter values optimizes the performance of your application and helps prevent SQL injection attacks.

Elenco dei parametri

statement

This must be a valid SQL statement for the target database server.

driver_options

This array holds one or more key=>value pairs to set attribute values for the PDOStatement object that this method returns. You would most commonly use this to set the PDO_ATTR_CURSOR value to PDO_CURSOR_SCROLL to request a scrollable cursor.

Valori restituiti

If the database server successfully prepares the statement, PDO::prepare() returns a PDOStatement object.

Esempi

Esempio 1. Prepare an SQL statement with named parameters

<?php
/* Execute a prepared statement by passing an array of values */
$sql = 'SELECT name, colour, calories
    FROM fruit
    WHERE calories < :calories AND colour = :colour'
$sth = $dbh->prepare($sql, array(PDO_ATTR_CURSOR, PDO_CURSOR_FWDONLY));
$sth->execute(array(':calories' => 150, ':colour' => 'red'));
$red = $sth->fetchAll();
$sth->execute(array(':calories' => 175, ':colour' => 'yellow'));
$yellow = $sth->fetchAll();
?>

Esempio 2. Prepare an SQL statement with question mark parameters

<?php
/* Execute a prepared statement by passing an array of values */
$sth = $dbh->prepare('SELECT name, colour, calories
    FROM fruit
    WHERE calories < ? AND colour = ?'
);
$sth->execute(array(150, 'red'));
$red = $sth->fetchAll();
$sth->execute(array(175, 'yellow'));
$yellow = $sth->fetchAll();
?>

Vedere anche:

PDO::exec()
PDO::query()
PDOStatement::execute()

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Generated: 2007-01-26 17:56:31