hi, i am making a database for an accounting/sales type system similar to a car sales database and would like to make some transactions for the following real world actions salesman creates new product shipped onto floor (itempk, car make, year, price).   salesman changes price.   salesman creates sale entry for product sold (salespk, itemforeignkey, price sold, salesman).   salesman cancels item for removed product.   salesman cancels sale for cancelled sale    the examples i have found online are too generic...like this is a transaction... i would like something resembling what i am trying to do to understand it.  anybody have some good similar or related sql examples i can look at to design these? do people use transactions for sales databases?  or if you have done this kind of sql transaction before could you make an outline for how these could be made?  thanks  my thread so far on stack overflow... http://stackoverflow.com/q/4975484/613799