Magento

How to write a Custom SQL Query Magento

To select the data

$read = Mage::getSingleton(‘core/resource’)->getConnection(‘core_read’);;
$selectQry = “SELECT * FROM catalog_category_entity”;
$write->query($selectQry);

To add/modify data

$write = Mage::getSingleton(‘core/resource’)->getConnection(‘core_write’);
$updateQry = “UPDATE catalog_category_entity_varchar SET value=’three_columns’ WHERE attribute_id=’61’ “;
$write->query($updateQry);