magento--------------数据库操作

1
$collection = Mage::getModel('catalog/product')->getCollection();
$collection->getSelect()->where('e.entity_id in (?)', $ids);
$collection->addAttributeToSelect('*');
2
$resource = Mage::getSingleton('core/resource');
$read = $resource->getConnection('catalog_read');

$select = $read->select()
->from(array('cp'=>$categoryProductTable))
3
$categoryProductTable = $resource->getTableName('catalog/category_product');
4
$productEntityIntTable = (string)Mage::getConfig()->getTablePrefix().
5

通过读写适配器得到的是：
Varien_Db_Adapter_Pdo_Mysql extends Zend_Db_Adapter_Pdo_Mysql
然后通过select()方法得到的是：Varien_Db_Select extends Zend_Db_Select

$select = $this->_getReadAdapter()->select()
->from($this->getTable('store'))
->where('post_id = ?', $object->getId());


protected function _getReadAdapter()
{
return $this->_getConnection('read');
}


也就是说通过collection->getSelect（）和
Mage::getSingleton('core/resource')->getConnection('catalog_read')->select()得到的都是Varien_Db_Select extends Zend_Db_Select

故。。。。。。。。。。。很好使用，看好Varien_Db_Select 和Zend_Db_Select的方法，就可以随意的使用已经封装好的函数！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！！