pdo binding returns false in update - php

Question

I have some issues with an update script. I bind my values but it returns false and I cannot see what I am doing wrong.
I am running this:
$row = $db->query('
UPDATE '. $config->db_prefix .'_adverts
SET ad_type = ?,
title = ?,
text = ?,
price = ?,
category = ?,
condition = ?
WHERE aid = ?')
->bind(1, $ad_type)
->bind(2, $title)
->bind(3, $text)
->bind(4, $price)
->bind(5, $category)
->bind(6, $condition)
->bind(7, $aid)->execute();
}
The bind function is this:
public function bind($pos, $value, $type = null) {
if( is_null($type) ) {
switch( true ) {
case is_int($value):
$type = PDO::PARAM_INT;
break;
case is_bool($value):
$type = PDO::PARAM_BOOL;
break;
case is_null($value):
$type = PDO::PARAM_NULL;
break;
default:
$type = PDO::PARAM_STR;
}
}
$this->stmt->bindValue($pos, $value, $type);
return $this;
}
a var_dump($this) gives me:
object(DB)#1 (2) { ["dbh":protected]=> object(PDO)#2 (0) { } ["stmt":protected]=> object(PDOStatement)#15 (1) { ["queryString"]=> string(211) " UPDATE rno_adverts SET ad_type = ?, title = ?, text = ?, price = ?, category = ?, condition = ? WHERE aid = ?" } }
but I can't see what is wrong.
EDIT:
query function is this:
public function query($query) {
$this->stmt = $this->dbh->prepare($query);
return $this;
}
and execute is this:
public function execute($var = null) {
return $this->stmt->execute($var);
}
ERROR:
Uncaught exception 'PDOException' with message 'SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'condition = 3 WHERE aid = 1'
The output of the query:
UPDATE rno_adverts SET ad_type = 3, title = "Gul bil", text = "En flot gul bil med hvide striber", price = 500, category = 4, condition = 3 WHERE aid = 1
I have gone blind on this query so I can't see what the problem is. If I remove category and condition, it works without problems. Both fields are INT NOT NULL in the database.

Answer 1

You can only use the bind functions with prepared statements. ->query() is for generating queries where you already know all the values/variables of a query beforehand.

Answer 2

Just get rid of this bind function and be all right
$sql = 'UPDATE '. $config->db_prefix .'_adverts SET
ad_type = ?, title = ?, text = ?, price = ?, category = ?, condition = ?
WHERE aid = ?';
$db->query($sql);
$db->execute(array($ad_type, $title, $text, $price, $category, $condition, $aid));

Answer 3

From your question one can not say specifically where the error is located. I therefore suggest you add more error checks first, e.g. with bindvalue(), you don't check the return value:
$this->stmt->bindValue($pos, $value, $type);
Instead throw an exception if this failed:
$bind = $this->stmt->bindValue($pos, $value, $type);
if (!$bind) {
throw new Exception(sprintf("Unable to bind parameter %s with a value of type #%d", $pos, $type));
}
This will prevent you have problems binding a value but it got unnoticed.
Similar with the execution. If you want to provide information why it fails, you need to read out the error information and throw an exception.