Is there any function in sql to apply customize fields values and get those values in where clause

for example i have data in sql table like this id event_name duration 1 Demo 20-mins 2 Party 5-hours 3 Camp 4-days

and I'm getting the mins , so i want to update these fields first in the mins than put them in the where clause like below

$product_result->where(CommonHelper::getProductDuration('duration'),"=", $request->duration);

via Chebli Mohamed