Question

Say I have a model Product from a table with id and in_stock fields. I only require to update the the in_stock value to (in_stock + added_stock). Is there a way to update it using the Yii functions without creating an instance of the model? I tried

Product::model()->updateByPk($id,array('in_stock'=>'in_stock+'.$added_stock));

but it didn’t work.
Any solutions are welcome.

Answer 1

I’m guessing you intended that $added_stock is a local PHP variable? If so this is probably the best way:

Product::model()->updateCounters(
    array('in_stock' => $added_stock), 
    array('condition'=>'id = :id'),
    array(':id' => $id)

);

That should work to add an arbitrary amount to a field without querying the record.
It will also cast the $added_stock variable into an integer before hand so there’s no worry of SQL injection or need to place it in a parameter.

P.S works with decimals too. Although I don’t think I want to know why you have to deal with fractions of units of stock ?? 🙂