Mal ejemplo
"The process of selecting a primary key is somewhat similar to that of a presidential election. Every four years, several people run for the office of president of the United States. These individuals are known as 'candidates' and they all have all of the qualifications required to become president. A national election is held, and a single individual from the pool of available presidential candidates is elected to serve as the country's official president. Similarly, you identify each qualified candidate key in the table, run your own election, and select one of them to become the official primary key of the table. You've already identified the candidates, so now it's election time!"
¡¡¿¿eso qué???!!
Mal ejemplo, muy mal ejemplo, muy mamón ejemplo