Magento 1.7 – How Does the Database Structure Connect Review Summaries to Review Details?

First thing you need to do is create a connection in your module's config.xml. It should look similar to the default_setup in your /app/etc/local.xml. Here you can specify the host to be localhost and then set a different dbname or you can specify a different host completely. I have also used a socket before which works also.

<resources>
    <new_db>
        <connection>
            <host><![CDATA[localhost]]></host>
            <username><![CDATA[db_username]]></username>
            <password><![CDATA[db_password]]></password>
            <dbname><![CDATA[db_name]]></dbname>
            <model>mysql4</model>
            <type>pdo_mysql</type>
            <active>1</active>
        </connection>
    </new_db>
</resources>

Now after this you will be able to connect to this database an perform queries as follows:

$new_db_resource = Mage::getSingleton('core/resource');
$connection = $new_db_resource->getConnection('new_db');
$results    = $connection->query('SELECT * FROM table');

If you want to do this via a model then you can specify the read, write and setup resources as follows. This will again be done inside the resources node in your config.xml and you should replace test with what your model has been setup as.

<resources>
    <new_db>
        <connection>
            <host><![CDATA[localhost]]></host>
            <username><![CDATA[db_username]]></username>
            <password><![CDATA[db_password]]></password>
            <dbname><![CDATA[db_name]]></dbname>
            <model>mysql4</model>
            <type>pdo_mysql</type>
            <active>1</active>
        </connection>
    </new_db>
    <test_write>
        <connection>
            <use>new_db</use>
        </connection>
    </test_write>
    <test_read>
        <connection>
            <use>new_db</use>
        </connection>
    </test_read>
    <test_setup>
        <connection>
            <use>new_db</use>
        </connection>
    </test_setup>
</resources>
<models>
    <test>
        <class>My_Test_Model</class>
        <resourceModel>test_resource</resourceModel>
    </test>
    <test_resource>
        <class>My_Test_Model_Resource</class>
        <entities>
            <test>
                <table>test</table>
            </test>
        </entities>
    </test_resource>
</models>

The model itself will try to find it's connection information in the function getConnection /app/code/core/Mage/Core/Model/Resource.php. If you log the $name passed in you will see values like poll_write, tag_write and cms_read where the first part matches the models section in the config.xml, in our case you would see test_write, test_read or test_setup. If it cannot find a connection matching this then it will use the default connections core_read, core_write or core_setup

The problem is that the _beforeSave on the Mage_Review_Model_Resource_Review sets the created_at value when there is no id for the review, so for new reviews.

protected function _beforeSave(Mage_Core_Model_Abstract $object)
{
    if (!$object->getId()) {
        $object->setCreatedAt(Mage::getSingleton('core/date')->gmtDate());
    }
    if ($object->hasData('stores') && is_array($object->getStores())) {
        $stores = $object->getStores();
        $stores[] = 0;
        $object->setStores($stores);
    } elseif ($object->hasData('stores')) {
        $object->setStores(array($object->getStores(), 0));
    }
    return $this;
}

You could do one of the following:

1. Rewrite the resource and change the function,
2. Save first and then save again
3. There may be another option that I cannot think of at the moment :(