Dreaded date issues

[Bilbozilla]

Hi there,

I am trying to update an expiration date into my mysql database.

My field 'activity_exp' is a is classified as a "date" field.

The variable $num_days is the number of days I wish to add to the activity_exp field.

I'm confused as to the context of "Update" and adding the number of days to this query.

[dagon]

$sup="update TABLE set activity_exp=DATE_ADD(activity_exp,INTERVAL $num_days DAY) WHERE XXX";

or

$sup="update TABLE set activity_exp=activity_exp + $num_days DAY WHERE XXX";