R Programming By Example

The too-much-empty-space problem

Let's say we have a sales record; what happens if we get a message related to that order from our customer? Well, we simply add the data to the corresponding columns DATE, STARS, and MESSAGE. What happens if we get another message related to the same order? Well, a possible solution would be to add a new combination of DATE, STARS, and MESSAGE for the new message, but names would collapse.

How would we differentiate among them? Well, we can append a number indicating the actual message number. Then, we would have DATE_1, STARS_1, and MESSAGE_1 for the first message, and DATE_2, STARS_2, and MESSAGE_2 for the second message. That would fix it, wouldn't it? What happens if we get a third, or more, messages related ...