Menu
I have a column update_date in a table and type is timestamp. I set the deault value by using phpmyadmin drop down menu to CURRENT_TIMESTAMP. But later when ever I run sql UPDATE x SET ... it updates the timestamp column if only there is a changes in any of the columns. What I would like to achieve is that whether there is a change or not set the current time everytime the update sql runs. Is there any way of doing it in the mysql or I need to set the update_date explicitly every time the update is called?
Thank you
703
An auto-updated column is automatically updated to the current timestamp when the value of any other column in the row is changed from its current value. An auto-updated column remains unchanged if all other columns are set to their current values.
Timestamps are also lighter on the database and indexed faster. The DATETIME type is used when you need values that contain both date and time information. MySQL retrieves and displays DATETIME values in YYYY-MM-DD HH:MM:SS format.
The DATETIME type is used for values that contain both date and time parts. MySQL retrieves and displays DATETIME values in ' YYYY-MM-DD hh:mm:ss ' format. The supported range is '1000-01-01 00:00:00' to '9999-12-31 23:59:59' . The TIMESTAMP data type is used for values that contain both date and time parts.
You can use the timestamp column as other posters mentioned. Here is the SQL you can use to add the column in: ALTER TABLE `table1` ADD `lastUpdated` TIMESTAMP ON UPDATE CURRENT_TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ; This adds a column called 'lastUpdated' with a default value of the current date/time.
You need to explicitly update the column. From the MySQL manual, TIMESTAMP properties:
The auto-update TIMESTAMP column, if there is one, is automatically updated to the current timestamp when the value of any other column in the row is changed from its current value. If all other columns are set to their current values, the TIMESTAMP column does not change. Automatic updating does not apply if the TIMESTAMP column is explicitly assigned a value other than NULL.
Emphasis mine.
153
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
