convert datatype varchar to in magento collection

Question

i have magento collection

Mage::getResourceModel('customizebundles/customizebundles_collection')
                            ->distinct(true)->addFieldToSelect('validity')
                            ->setOrder('validity', 'asc');

how can i convert validity column varchar to unsigned like

SELECT DISTINCT validity FROM customize_bundles AS main_table order by cast(validity as unsigned)

Answer 1

Mage::getResourceModel('customizebundles/customizebundles_collection')
      ->distinct(true)->addFieldToSelect('validity')
      ->setOrder(new Zend_Db_Expr('cast(validity as unsigned)'), 'asc');

using Zend_Db_Expr will get you the solution.

Answer 2

you can set cast as mention @RT

$collection->setOrder(new Zend_Db_Expr("cast(validity as unsigned)"), 'asc')

or

 $collection->select()->order(new Zend_Db_Expr("CAST(validity AS unsigned )",'asc'));