What is causing SQLSTATE[42000]: Syntax error or access violation: 1064 when trying to Group Tables?

Question

I have been trying to figure out what is causing the exception when attempting to create a join for my Collections and group them with the main_table.

Here is the code from my Collection.php

<?php

class Companyname_CheckoutComments_Model_Resource_Comment_Collection extends Mage_Core_Model_Resource_Db_Collection_Abstract{


    protected function _construct() {

        $this->_init('checkoutcomments/comment');
    }
    public function addCustomerFilter($customer){

        $select = $this->getSelect();
        if ($customer->getId()){
            $select->where('order.customer_id?', $customer->getId());
        } else {
            //Force empty result set for not logged in customers
            $select->where('1=0');
        }

        $select->join(array('order' => $this->getTable('sales/order')),
                'order.entity_id = main_table.order_id',
                array('status', 'created_at'));

        $select->join(array('order_item' => $this->getTable('sales/order_item')),
                'order_item.order_id = main_table.order_id
                AND order_item.parent_item_id IS NULL ',
                array());

        /** Mage_Core_Model_Resource_Helper_Mysql4 */
        Mage::getResourceHelper('core')->addGroupConcatColumn($select, 'product_names', 'order_item.name', ', ' );
        $select->group('main_table.comment_id');
        return $this;
    }
}

The line that is giving me grief is:

$select->group('main_table.comment_id');

As it throws an error that I'm can't seem to fix

QLSTATE[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 ''2') GROUP BY `main_table`.`comment_id`' at line 4

SELECT `main_table`.*, `order`.`status`, `order`.`created_at`, GROUP_CONCAT(order_item.name SEPARATOR ', ') AS `product_names` FROM `checkout_comments` AS `main_table` INNER JOIN `sales_flat_order` AS `order` ON order.entity_id = main_table.order_id INNER JOIN `sales_flat_order_item` AS `order_item` ON order_item.order_id = main_table.order_id AND order_item.parent_item_id IS NULL WHERE (order.customer_id'2') GROUP BY `main_table`.`comment_id`

If anyone knows the correct syntax to use please could you kindly advise or if there is some error in my code that I have missed.

Thanks in advance guys!

Answer 1

The problem was indeed line 4

$select->where('order.customer_id?', $customer->getId());

Has to be

$select->where('order.customer_id=?', $customer->getId());