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PDOStatement::bindParam

(no version information, might be only in CVS)

PDOStatement::bindParam --  Binds a parameter to a the specified variable name

Description

bool PDOStatement::bindParam ( mixed parameter, mixed &variable [, int data_type [, int length]] )

Warning

This function is EXPERIMENTAL. The behaviour of this function, the name of this function, and anything else documented about this function may change without notice in a future release of PHP. Use this function at your own risk.

Binds an SQL statement parameter to the specified variable name. The SQL statement parameter can either be a named placeholder or a question mark placeholder.

Output parameters will set the value of the bound PHP variable to the value returned by the database when the SQL statement is executed. This enables you to call stored procedures with output or input/output parameters, for example, for databases that support such features.

For non-NULL input-only variables, you can pass an array of input values to PDOStatement::execute() instead.

Parameters

parameter

Parameter identifier. For a prepared statement using named placeholders, this will be a parameter name of the form :name. For a prepared statement using question mark placeholders, this will be the 1-indexed position of the parameter.

variable

Name of the PHP variable to bind to the SQL statement parameter.

data_type

Explicit data type for the parameter using the PDO_PARAM_* constants. To return an INOUT parameter from a stored procedure, use the bitwise OR operator to set the PDO_PARAM_INPUT_OUTPUT bits for the data_type parameter.

To pass a NULL value as an input parameter, declare the PDO_PARAM_NULL constant.

length

Length of the data type. To indicate that a parameter is an OUT parameter from a stored procedure, you must explicitly set the length.

Examples

Example 1. Execute a prepared statement with named placeholders

<?php
/* Execute a prepared statement by binding PHP variables */
$calories = 150;
$colour = 'red';
$sth = $dbh->prepare('SELECT name, colour, calories
    FROM fruit
    WHERE calories < :calories AND colour = :colour');
$sth->bindParam(':calories', $calories, PDO_PARAM_INT);
$sth->bindParam(':colour', $colour, PDO_PARAM_STR, 12);
$sth->execute();
?>

Example 2. Execute a prepared statement with question mark placeholders

<?php
/* Execute a prepared statement by binding PHP variables */
$calories = 150;
$colour = 'red';
$sth = $dbh->prepare('SELECT name, colour, calories
    FROM fruit
    WHERE calories < ? AND colour = ?');
$sth->bindParam(1, $calories, PDO_PARAM_INT);
$sth->bindParam(2, $colour, PDO_PARAM_STR, 12);
$sth->execute();
?>

Example 3. Pass a NULL value into a prepared statement

<?php
/* Execute a prepared statement by binding PHP variables */
$calories = 150;
$colour = 'red';
$sth = $dbh->prepare('SELECT name, colour, calories
    FROM fruit
    WHERE calories < :calories AND colour = :colour');
$sth->bindParam(':calories', $calories, PDO_PARAM_INT);

/* Find fruit with a NULL value in the colour column */
$sth->bindParam(':colour', $colour, PDO_PARAM_NULL);

$sth->execute();
?>

Example 4. Call a stored procedure with an INOUT parameter

<?php
/* Call a stored procedure with an INOUT parameter */
$colour = 'red';
$sth = $dbh->prepare('CALL puree_fruit(?)');
$sth->bindParam(1, $colour, PDO_PARAM_STR|PDO_PARAM_INPUT_OUTPUT, 12);
$sth->execute();
print("After pureeing fruit, the colour is: $colour");
?>

See Also

PDO::prepare()
PDOStatement::execute()

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