Question

I have a table that records the mailing list subscriptions for subscribers.

CREATE TABLE IF NOT EXISTS `subscriber_list` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `subscriber_id` int(11) NOT NULL,
  `account_id` int(11) NOT NULL,
  `list_id` int(11) NOT NULL,
  `date_entered_gmt` timestamp NULL DEFAULT NULL,
  PRIMARY KEY (`id`),
  KEY `subscriber_id_account_id_list_id` (`subscriber_id`,`account_id`,`list_id`),
  KEY `list_id_account_id` (`list_id`,`account_id`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci AUTO_INCREMENT=1454722 ;

In the application, which uses the table, there is function that allows all subscribers within a mailing list to be subscribed to another.

I was going to use a subquery to get all the current subscribers of the mailing list that will be subscribed to the new selected mailing list and some how with this list of subscribers insert a new mailing list record for each defining the new subscription but the mailing list can reach up to 250,000 subscribers so I am not sure how this should be done.

Cheers

Marc

Answer 1

You can use INSERT … SELECT something like this –

INSERT INTO subscriber_list (subscriber_id, account_id, list_id, date_entered_gmt)
SELECT subscriber_id, account_id, 4, NOW()
FROM subscriber_list
WHERE list_id = 3

In response to your comment I have updated the values in this query. This will –

SELECT subscriber_id, account_id, 4, NOW()
FROM subscriber_list
WHERE list_id = 3

and insert them straight into the subscriber list table. So, if the values in the SELECT are those that you want to insert this will suit your scenario.