I'm creating a website for a simple poll from registered users. Every month, registered users only allowed to vote 5x for a poll.
Now, i'm going to create a server event with HEIDI SQL on 2 tables which will reset their 5 times votes on each month to 0
Here's my exe code:
CREATE EVENT `resetvalue`
ON SCHEDULE
EVERY 1 MONTH STARTS '2017-10-01 00:00:00'
ON COMPLETION PRESERVE
ENABLE
COMMENT 'Im going to reset this every month'
DO BEGIN
UPDATE tbl_users SET statusmonth = 0
UPDATE tbl_poll SET status1 = 0
UPDATE tbl_poll SET status2 = 0
END
Is this the correct code?
Unfortunately, I asked my friend and then he gave another code that look like this:
DELIMITER $$
CREATE EVENT `dbname`.`resetvalue`
ON SCHEDULE EVERY 1 MONTH
STARTS '2011-06-21 01:00:00'
ON COMPLETION NOT PRESERVE
ENABLE
DO BEGIN
/(sql_statements)
END$$
DELIMITER ;
I got confused, which one is the correct code? What is a DELIMiTER anyway?
Below is a difference for your event with respect to your friend's event.
Your event will run on 1st of every month at 12:00 am and start date of event is 2017-10-01 00:00:00 but your friend's event will run on 21st at 12:00 am of every month and start date is 2011-06-21 01:00:00.
Your event will not deleted once event is completed. But your friend's event code will be removed once it will done. Here both events are never ending it's affect only if it's 5 times to run or you disable an event.
Other then this I think it's same. For more details you can refer MySQL event scheduler documentation.
https://dev.mysql.com/doc/refman/5.7/en/events-overview.html
Related
I have the program below whose goal is to update col2 every day at 23h59min59s. the problem is that we have accounts all over Africa and europe. I would like the program to run every day at 23:59:59 depending on the timezone of each account. For example, if the account is in France, the DBMS should automatically change the value of col2. if the account is in cameroon and it is 23h, col2 must be updated.
DROP EVENT IF EXISTS `updateColumn`;
DELIMITER $$
CREATE EVENT `updateColumn`
ON SCHEDULE EVERY 1 DAY STARTS '2019-04-15 23:59:59' // I Want 23h59min59s du timezone
ON COMPLETION PRESERVE
DO BEGIN
update ma_table set col2=col1;
END$$
DELIMITER ;
the column is actually updated but the update dates aren't good.
I think, that You need to add information about record timezone in the row (ACCOUNT). I.e. column GMT_TIMEZONE_INFO. Then in this event update on each hour where Server time + GMT_TIMEZONE_INFO is midnight(or whatever time you want).
DELIMETER $$
CREATE EVENT loan_balance ON SCHEDULE EVERY '1' MONTH AND '5' DAYS
DO BEGIN UPDATE users SET loan_balance = total_loans_collected -
total_loans_paid;
END$$
DELIMETER;
Hello! I want to update this table on the 5th of every month and not just monthly. The "AND '5' DAYS isn't making it work.
You need a slightly different ON SCHEDULE phrase.
AT '2018-04-01 03:01' + INTERVAL 5 DAY EVERY MONTH
fires your event at 03:01 local time on the fifth day of every month.
03:01 is a good time for a scheduled job because it doesn't get messed up by standard-time / daylight-time switchovers.
Instead of using a trigger to update the loan_balance column, you can turn it into a generated column.
ALTER TABLE users MODIFY COLUMN loan_balance INT GENERATED ALWAYS AS
(total_loans_collected - total_loans_paid) STORED;
Unless I'm missing something, I believe this is the most optimal approach, and it is certainly easier to maintain.
I have a table in my MYSQL database called sale as shown below:
I want to auto delete the sales that are 3 days old and not validated,
I create event but unfortunately it doesn't work here's my code :
CREATE EVENT `delete_sale` ON SCHEDULE EVERY 1 HOUR DO DELETE FROM sale WHERE sale.is_validated = 0 and sale.date < DATE_SUB(NOW(), INTERVAL 3 DAY)
My best guess is that your event is working, but it's only firing once then deactivating. To fix that, you should add the "ON XOMPLETION PRESERVE" line. Another possibility is that it's not loading properly because it can't quite parse your event code. To really hold MySQL's hand with this, try treating it like a multi statement event, changing the delimiter and adding BEGIN and END. Something like this:
DELIMITER &&
CREATE EVENT `delete_sale`
ON SCHEDULE EVERY 1 HOUR
ON COMPLETION PRESERVE
DO
BEGIN
DELETE FROM sale WHERE sale.is_validated = 0 and sale.date < DATE_SUB(NOW(), INTERVAL 3 DAY);
END &&
DELIMITER ;
the problem resolved by enabling event_scheduler with the following query SET GLOBAL event_scheduler = ON;
I have a MySQL database with one big table in it. After a while, it becomes too full and performance degrades. Every Sunday, I want to delete rows whose last update is older than a certain number of days ago.
How do I do that?
Make a Scheduled Event to run your query every night. Check out Event Scheduler as well.
CREATE EVENT `purge_table` ON SCHEDULE
EVERY 1 DAY
ON COMPLETION NOT PRESERVE
ENABLE
COMMENT ''
DO BEGIN
DELETE FROM my_table WHERE my_timestamp_field <= now() - INTERVAL 5 DAY
END
What is the table design? Do you have a column with a timestamp?
Assuming you do, you could use that timestamp value with a datediff(your_date,CURDATE()) in a delete command.
Delete from table where datediff(date_col, CURDATE ()) > your_num_days.
Self Answer
Make a web server that sends the following SQL to the database every weekend:
DELETE FROM table WHERE timestamp < DATE_SUB(NOW(), INTERVAL 7 DAY);
or
DELETE FROM table
WHERE timestamp < UNIX_TIMESTAMP(DATE_SUB(NOW(), INTERVAL 7 DAY))
I might need locking to prevent accumulation of jobs, like so:
DELIMITER //
CREATE EVENT testlock_event ON SCHEDULE EVERY 2 SECOND DO
BEGIN
DECLARE CONTINUE HANDLER FOR SQLEXCEPTION
BEGIN
DO RELEASE_LOCK('testlock_event');
END;
IF GET_LOCK('testlock_event', 0) THEN
-- add some business logic here, for example:
-- insert into test.testlock_event values(NULL, NOW());
END IF;
DO RELEASE_LOCK('testlock_event');
END;
//
DELIMITER ;
Final answer:
CREATE EVENT `purge_table` ON SCHEDULE
EVERY 1 DAY
ON COMPLETION NOT PRESERVE
ENABLE
COMMENT ''
DO BEGIN
IF GET_LOCK('purge_table', 0) THEN
DELETE FROM table WHERE timestamp < UNIX_TIMESTAMP(DATE_SUB(NOW(), INTERVAL 7 DAY));
END;
Maybe you can provide more information on how you are pushing the data to the DB and how you are working on the DB in general? Therefore we can help you and don't have to struggle with the dark...
I'll provide an easy solution: It's kind of workaround, but works:
Everytime you touch the data you update a time stamp in the updated rows.
Therefore you could easily filter them out every sunday.
UPDATE
The answer, the author provided by himself, was discussed at Stackoverflow and seems not to work in exactly that way, compare the discussion.
I am using SAILS JS and mysql adapter is being used. I have a model named as User with the following fields ID, USERNAME, EMAIL, ACTIVE_STATUS and CREATED_DATE.
By Default, active_status is set as 0. I want to update the status is 1 when created_date + 3 days is equal on Today.
Kindly suggest any possible ways to do this.
Hope you can use MySQL’s Event Scheduler
Activate it by: SET GLOBAL event_scheduler = ON;
Create event syntax:
CREATE EVENT `event_name`
ON SCHEDULE schedule
[ON COMPLETION [NOT] PRESERVE]
[ENABLE | DISABLE | DISABLE ON SLAVE]
DO BEGIN
-- event body
END;
The schedule can be assigned various settings, e.g.
Run once on a specific date/time:
AT ‘YYYY-MM-DD HH:MM.SS’
e.g. AT ‘2011-06-01 02:00.00’
Run once after a specific period has elapsed:
AT CURRENT_TIMESTAMP + INTERVAL n [HOUR|MONTH|WEEK|DAY|MINUTE]
e.g. AT CURRENT_TIMESTAMP + INTERVAL 1 DAY
Run at specific intervals forever:
EVERY n [HOUR|MONTH|WEEK|DAY|MINUTE]
e.g. EVERY 1 DAY
Run at specific intervals during a specific period:
EVERY n [HOUR|MONTH|WEEK|DAY|MINUTE] STARTS date ENDS date
e.g. EVERY 1 DAY STARTS CURRENT_TIMESTAMP + INTERVAL 1 WEEK ENDS ‘2012-01-01 00:00.00’
Example:
SET GLOBAL event_scheduler = ON; -- enable event scheduler.
SELECT ##event_scheduler; -- check whether event scheduler is ON/OFF
CREATE EVENT e_store_ts -- create your event
ON SCHEDULE
EVERY 24 HOURS -- run every 24 hours
DO
UPDATE myschema.users set active_status = 1
Refer: http://dev.mysql.com/doc/refman/5.5/en/create-event.html