PDOStatement::bindParam
Binds a parameter to the specified variable name
Description
public bool PDOStatement::bindParam(
stringint $param,
mixed &$var,
int $type = PDO::PARAM_STR,
int $maxLength = 0,
mixed $driverOptions = null
)
Most parameters are input parameters, that is, parameters that are used
in a read-only fashion to build up the query (but may nonetheless be cast
according to type). Some drivers support the
invocation of stored procedures that return data as output parameters,
and some also as input/output parameters that both send in data and are
updated to receive it.
Parameters
-
param
-
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.
-
var
-
Name of the PHP variable to bind to the SQL statement parameter.
-
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 type parameter.
-
maxLength
-
Length of the data type. To indicate that a parameter is an OUT
parameter from a stored procedure, you must explicitly set the
length.
Meaningful only when type parameter is PDO::PARAM_INPUT_OUTPUT.
-
driverOptions
-
Return Values
Returns true on success or false on failure.
Errors/Exceptions
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.
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);
/* Names can be prefixed with colons ":" too (optional) */
$sth->bindParam(':colour', $colour, PDO::PARAM_STR);
$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);
$sth->execute();
?>
Example #3 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
- PDOStatement::bindValue