Save phone calls data in a DB?

How would you save this data on a database: An user can make phone calls (id, date, hour, duration, outcome).

The "outcome" can be, for example, to recall the client on another day (so I have to save the date, the hour, etc of this "future" ca开发者_高级运维ll).

How would you manage this data on a db?

At the moment i have only a "Call" table.

One way would be to add an ENUM field specifying what type of call it is. So all calls actually taken would have that field set to "taken", and any future calls added would be "future", or something like that.

In your 'result' field of the original call, you could also reference the ID of the new call if that is useful.