CODEWITHSUNDEEP
phppdo
user3790186
user3790186

Reputation: 269

Cannot pass parameter 2 by reference error in php PDO

I am getting the error: Cannot pass parameter 2 by reference in.....

in this line...

$stmt1->bindParam(':value', $_SESSION['quantity'.$i] * $_SESSION['price'.$i], PDO::PARAM_STR);

What is wrong with code above ??

Upvotes: 2

Views: 8253

Answers (2)

Álvaro González
Álvaro González

Reputation: 146490

I'd say it's the typical confusion between PDO:bindParam() and what you probably intended to use: PDO:bindValue().

PDOStatement::bindParam

Binds a PHP variable to a corresponding named or question mark placeholder in the SQL statement that was used to prepare the statement. Unlike PDOStatement::bindValue(), the variable is bound as a reference and will only be evaluated at the time that PDOStatement::execute() is called.

PDOStatement::bindValue

Binds a value to a corresponding named or question mark placeholder in the SQL statement that was used to prepare the statement.

Upvotes: 7

Adam
Adam

Reputation: 6773

It expects the second paramter to be a variable which can be passed by reference. Assuming $stmt1is a PDO statement then, as the docs for bindparam say

Unlike PDOStatement::bindValue(), the variable is bound as a reference and will only be evaluated at the time that PDOStatement::execute() is called.

Your second param is an expression ($_SESSION['quantity'.$i] * $_SESSION['price'.$i]) not a variable. Since you appear to want to evaluate the exptression now, I guess you should used bindValue() instead.

Upvotes: 5

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