UK Specialists in Ruby on Rails, Exalead, AWS, Consultancy - Conditional duplicate key updates with MySQL Comments

Comment on 'Conditional duplicate key updates with MySQL' by James

2011-11-29T21:05:26Z

I was trying to figure out a way for multiple listeners that may receive some of the same events to be able to automatically de-duplicate them without having to use transactions (not supported by my engine) or an IPC/HA mechanism between the listeners (unnecessarily complex). Great post, still solving problems almost 2 years later!

Comment on 'Conditional duplicate key updates with MySQL' by Rob Anderton

2011-10-28T22:45:23Z

That's the point of this story - to show a workaround that does work in MySQL :)

Comment on 'Conditional duplicate key updates with MySQL' by pol2095

2011-10-28T14:40:43Z

INSERT INTO daily_events (created_on, last_event_id, last_event_created_at)
VALUES ('2010-01-19', 23, '2010-01-19 10:23:11')
ON DUPLICATE KEY UPDATE
last_event_id = VALUES(last_event_id),
last_event_created_at = VALUES(last_event_created_at)
WHERE last_event_created_at < VALUES(last_event_created_at);

WHERE doesn't work in mysql

Comment on 'Conditional duplicate key updates with MySQL' by Rob Anderton

2011-10-28T10:34:52Z

@rakesh: if the insert or update should only happen when the condition is true, then that sounds like a slightly different problem and the condition should be added as a WHERE clause on the SELECT, so something like:

insert into maintenance.sap_promotions_item_level 
select * from pos.promotions_item_level 
WHERE (pos.promotions_item_level.modified_on > select max(modified_on) from maintenance.sap_promotions_item_level)
ON DUPLICATE KEY  UPDATE 
maintenance.sap_promotions_item_level.SCALING_ID=pos.promotions_item_level.SCALING_ID,
maintenance.sap_promotions_item_level.DISC_INDICATOR=pos.promotions_item_level.DISC_INDICATOR,
maintenance.sap_promotions_item_level.QTY_QUALIFIER=pos.promotions_item_level.QTY_QUALIFIER,
maintenance.sap_promotions_item_level.DISCOUNT_PERCENT=pos.promotions_item_level.DISCOUNT_PERCENT,
maintenance.sap_promotions_item_level.PRICE_OFF_VALUE=pos.promotions_item_level.PRICE_OFF_VALUE,
maintenance.sap_promotions_item_level.PROMO_PRICE_VALUE=pos.promotions_item_level.PROMO_PRICE_VALUE,
maintenance.sap_promotions_item_level.FGOOD1_CODE=pos.promotions_item_level.FGOOD1_CODE,
maintenance.sap_promotions_item_level.FGOOD1_QTY=pos.promotions_item_level.FGOOD1_QTY,
maintenance.sap_promotions_item_level.FGOOD2_CODE=pos.promotions_item_level.FGOOD2_CODE,
maintenance.sap_promotions_item_level.FGOOD2_QTY=pos.promotions_item_level.FGOOD2_QTY,
maintenance.sap_promotions_item_level.FGOOD3_CODE=pos.promotions_item_level.FGOOD3_CODE,
maintenance.sap_promotions_item_level.FGOOD3_QTY=pos.promotions_item_level.FGOOD3_QTY,
maintenance.sap_promotions_item_level.FGOOD4_CODE=pos.promotions_item_level.FGOOD4_CODE,
maintenance.sap_promotions_item_level.FGOOD4_QTY=pos.promotions_item_level.FGOOD4_QTY,
maintenance.sap_promotions_item_level.VALID_FROM_DATE=pos.promotions_item_level.VALID_FROM_DATE,
maintenance.sap_promotions_item_level.VALID_TO_DATE=pos.promotions_item_level.VALID_TO_DATE,
maintenance.sap_promotions_item_level.modified_on=pos.promotions_item_level.modified_on;

But I may have misunderstood your situation.

@ionut: do you want one visit for a specific visitor per day? To handle the seen flag you'd INSERT a zero into the field and then set it to 1 in the ON DUPLICATE KEY UPDATE section. I'm guessing to handle the one per day, you may need to look at a subquery in the IF that checks if any records exist for the given date/visitor ID combination, but as with rakesh I may well have misunderstood what you're trying to do!

Comment on 'Conditional duplicate key updates with MySQL' by ionut

2011-10-20T10:03:15Z

hi maybe you can help i have the table

CREATE TABLE `visits` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `visitor` int(10) unsigned NOT NULL,
  `visited` int(10) unsigned NOT NULL,
  `when` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  `seen` tinyint(3) unsigned NOT NULL DEFAULT '0',
  PRIMARY KEY (`id`),
  KEY `visits_ibfk_2` (`visited`),
  KEY `visits_ibfk_1` (`visitor`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

can i use your method to insert only one visit per day and if is new to have seen = 0 ? i tried a lot of combinations (using your example) but no luck

Comment on 'Conditional duplicate key updates with MySQL' by rakesh

2011-09-27T09:20:17Z

insert into maintenance.sap_promotions_item_level 
select * from pos.promotions_item_level  ON DUPLICATE KEY  UPDATE 
maintenance.sap_promotions_item_level.SCALING_ID=pos.promotions_item_level.SCALING_ID,
maintenance.sap_promotions_item_level.DISC_INDICATOR=pos.promotions_item_level.DISC_INDICATOR,
maintenance.sap_promotions_item_level.QTY_QUALIFIER=pos.promotions_item_level.QTY_QUALIFIER,
maintenance.sap_promotions_item_level.DISCOUNT_PERCENT=pos.promotions_item_level.DISCOUNT_PERCENT,
maintenance.sap_promotions_item_level.PRICE_OFF_VALUE=pos.promotions_item_level.PRICE_OFF_VALUE,
maintenance.sap_promotions_item_level.PROMO_PRICE_VALUE=pos.promotions_item_level.PROMO_PRICE_VALUE,
maintenance.sap_promotions_item_level.FGOOD1_CODE=pos.promotions_item_level.FGOOD1_CODE,
maintenance.sap_promotions_item_level.FGOOD1_QTY=pos.promotions_item_level.FGOOD1_QTY,
maintenance.sap_promotions_item_level.FGOOD2_CODE=pos.promotions_item_level.FGOOD2_CODE,
maintenance.sap_promotions_item_level.FGOOD2_QTY=pos.promotions_item_level.FGOOD2_QTY,
maintenance.sap_promotions_item_level.FGOOD3_CODE=pos.promotions_item_level.FGOOD3_CODE,
maintenance.sap_promotions_item_level.FGOOD3_QTY=pos.promotions_item_level.FGOOD3_QTY,
maintenance.sap_promotions_item_level.FGOOD4_CODE=pos.promotions_item_level.FGOOD4_CODE,
maintenance.sap_promotions_item_level.FGOOD4_QTY=pos.promotions_item_level.FGOOD4_QTY,
maintenance.sap_promotions_item_level.VALID_FROM_DATE=pos.promotions_item_level.VALID_FROM_DATE,
maintenance.sap_promotions_item_level.VALID_TO_DATE=pos.promotions_item_level.VALID_TO_DATE,
maintenance.sap_promotions_item_level.modified_on=pos.promotions_item_level.modified_on;

I have to add the if or where condition to add the date constraint ie: if (pos.promotions_item_level.modified_on > select max(modified_on) from maintenance.sap_promotions_item_level) then only update or insert should happen.

thanks

Comment on 'Conditional duplicate key updates with MySQL' by Philippe

2010-12-15T20:33:29Z

Just saved me a couple hours of pulling my hair out... thanks !

Comment on 'Conditional duplicate key updates with MySQL' by Rob Anderton

2010-11-13T23:13:35Z

Have you tried something like this?

INSERT INTO visits(site, lastvisit)
VALUES (1, 2010-01-19 10:23:11')
ON DUPLICATE KEY UPDATE
lastvisit = IF(DATE_ADD(lastvisit, interval 7 minute) < NOW(), VALUES(lastvisit), lastvisit);

If that's no help, post the full query you're trying to perform and I'll take another look.

Comment on 'Conditional duplicate key updates with MySQL' by paul

2010-11-13T00:26:11Z

i just want the following condition in the IF part if it is true

if DATE_ADD(lastvisit, interval 7 minute) < NOW() then update

but I just don't seem to get the right syntax can anybody help me?

Comment on 'Conditional duplicate key updates with MySQL' by Jeremy James

2010-02-11T10:34:16Z

great idea to put the if clause as condition in the update part, i was wondering how to solve that problem!thanks for the hint best regards from germany