I went through lots of links but still I am confuse about the way that I could use.
I have mysql database at server side,when user hits server with some values, at same time I save current time of server also.(jsp is used at server side)
Now I want to update some values from row after specific interval of time from current time which saved in database.(Every row has different current time value.)
You will have to use the MySQL events. In this tutorial, you have an example of how to configure this via phpMyAdmin: http://www.youtube.com/watch?v=7ZRZoCsrKis.
Related
I would need to remove some data from the MySQL DB when the expire time has arrived.
Like, expire the cookie value on the server-side when user session time has arrived. It's like an automatic action. It's needs to do even the customer was not online. When he was back to the online he needs to login again. And it needs to do some works like reminder action. User can fix some time to bring some reminder notification. On that time server needs to fetch some data from the MySQL DB and sent it to the customer through the push notification automatically.
You need to do the following:
Add a column in your table to store the expiry date/time using default systime + expiry. You want the time to be generated by the DB and not your app code, so it will be exact.
Index this column with BTree, not Hash. You need this index.
Write a stored procedure to delete rows < current system time.
Create a mysql scheduled event to run every 1 minute to run your stored procedure.
I have table called race with a lap1, lap 2 and lap3 as the attribute. Now want to create a Trigger that will add the laps which has time as datatype. And also insert the added laps into the finish_time in the results table.results tablerace table
Don't do that. In real life, database server could have different time or different timezone configured. Or you can have bad timezone configured on your side when connection to database. It is always better use dates and times from PHP and don't rely on database settings until you have database fully under control.
I'm based in a certain timezone but my server is one hour ahead. When I save new records with a timestamp column, it displays the time as one hour ahead.
How will this affect me in the long run? How will I need to alter my queries to return my time instead of the server's time? Or should I not worry about this at all? I'm new to web dev...
After connecting to database execute query:
SET time_zone = 'Europe/London';
List of timezones: http://php.net/manual/en/timezones.php
Or change it via WordPress settings:
http://help.coschedule.com/hc/en-us/articles/214455448-How-To-Change-Your-WordPress-Timezone
I have two data environments 1) a data source 2) a production database powering a website. These two data environments are in two different timezones.
I am updating my production database incrementally by using
1. mysqldump - for syncing newly added records
2. sqlyog sja - for syncing updated records.
I have a column named modified_time (modified_time timestamp NOT NULL default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP) in each table to store the last modified time.
While syncing this data between two timezones I am not able to change the timezone.
I wanted to know how can I change the source timezone to target timezone while syncing
This is not possible at the db level and even if it were to be possible it would be inefficient, I would say deal with it in your application, its simple, all data is in a different timezone, so you just need to change it by a constant to get your time.
Again if the source data is using UTC (which is recommended) then you dont have any issue at all.
I have a development server that is getting crowded.
I would like to see what date the databases have been accessed to determine what ones can be deleted. Is there a way to do this?
The only thing I found when searching was for postgredb:
How to get last access/modification date of a PostgreSQL database?
If you have a table that always gets values inserted you can add a trigger to the update/insert. Inside this trigger you can set the current timestamp in a dedicated database, including the name of the database from which the insert took place.
This way the only requirement of your database is that it supports triggers.