Tatiane Stivelman

It worked very well, thanks

I'm doing a project that contains a stock, I first created the stock scaffold like this:

rails generate scaffold stock name:string amount:float kind:string

And then a stock_flow scaffold like this:

rails g scaffold stock_flow in_out:string time:datetime name:string amount:float kind:string origin_destiny:string stock:belongs_to

Now I want that every time that is inserted a new item at stock_flow, it searches the name inserted in the stock table and:
1) if it doesn't exists, creates a new item in stock (with the same name, amount and kind just inserted in stock_flow)
2) if it exists and the in_out field is "in" update the stock.amount to stock.amount+ the amount just inserted in stock_flow
3) if it exists and the in_out field is "out" update the stock.amount to stock.amount - the amount just inserted in stock_flow
I didn't change nothing in the code, so models, controllers and views are in the same way that when the scaffolds were generated.
I'm really lost and don't know how to do it, could somebody please help me?