I'm going to add a new column to a table, and the table has a lot of
records like this:

+------+--------+------+
| year | month | day |
+------+--------+------+
| 2004 | 10 | 24 |
+------+--------+------+

I know how to add the new column, but:
The new column should be of type date; that is contain the above data in
this form: '2004-10-24', so I'll be able to do calculations on the dates.

Is there a way to build that date string with mysql statements alone,
or is it better to apply a php-script to do this?

Salve Håkedal wrote:
> I'm going to add a new column to a table, and the table has a lot of
> records like this:
>
> +------+--------+------+
>> year | month | day |
> +------+--------+------+
>> 2004 | 10 | 24 |
> +------+--------+------+
>
> I know how to add the new column, but:
> The new column should be of type date; that is contain the above data
> in this form: '2004-10-24', so I'll be able to do calculations on the
> dates.
>
> Is there a way to build that date string with mysql statements alone,
> or is it better to apply a php-script to do this?

You can either concatenate the fields into a supported date string or use
the STR_TO_DATE function