I have been making tables with a modified row which is time stamped.
`modified` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
I am seeking to rename this as bookedinand timestamp the day of entry into the database.
i have looked on the net for a solution at sites like http://www.w3schools.com/sql/func_curdate.asp
And cant seem to find a solution that works or is what i need.
I tried to edit it in the databse myself but with no luck. as you can tell im a extremity novice
Instead of w3schools you really should use the actual MySQL documentations. http://dev.mysql.com/doc/refman/5.1/en/alter-table.html
alter table tablename change `modified` `bookedin` timestamp NOT NULL DEFAULT
CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP;
Or maybe just
alter table tablename change `modified` `bookedin` timestamp NOT NULL DEFAULT
CURRENT_TIMESTAMP;
I think the on update may just be part of the timestamp datatype. And, I think that altering the name of the table might cause all the rows to update their timestamp to the date you did it. So you might want to make a copy of the table and try it out first. I remember running into a problem like that once that made me switch from using TIMESTAMP to DATETIME.
Related
There's a log table with a TIMESTAMP column, that currently has precision down to the second.
This is not enough, cause sometimes multiple events happen in the same second, and this way we can't tell the order of the events happening.
I know this could be fixed with an automatically incremented ID (to put them in order of happening), but a Timestamp with millisecond precision is what I'm after since I would like to see how much time happens between two events.
If I change the columns default value from CURRENT_TIMESTAMP to CURRENT_TIMESTAMP(3), I get the following error in MySQL Workbench:
Executing:
ALTER TABLE `my_db`.`logs`
CHANGE COLUMN `timestamp` `timestamp` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP(6) ;
Operation failed: There was an error while applying the SQL script to the database.
ERROR 1067: Invalid default value for 'timestamp'
SQL Statement:
ALTER TABLE `my_db`.`logs`
CHANGE COLUMN `timestamp` `timestamp` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP(6)
I already have data in the table, which I wouldn't like to use, so I would like to alter this table.
Is it actually possible to alter the table this way, so from now on the timestamp column will be more precise?
PS:
I tried adding a new (totally blank) column with the added precision, but it threw the same error.
Your alter query has the (6) missing on a second spot:
ALTER TABLE `my_db`.`logs`
CHANGE COLUMN `timestamp` `timestamp` TIMESTAMP(6) NOT NULL DEFAULT
CURRENT_TIMESTAMP(6)
I have tried to Google this so I didn't have to ask, as i'm sure this is a simple task...
I am building an E-commerce site and would like to add the date and time a product is added into the product database?
Apologies if this is simple, but i have researched everywhere else first.
Thanks
This can just be part of your database architecture:
ALTER TABLE `products` ADD `created` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP
This will automatically add a timestamp to the column created whenever a row is created. For more information, try this: Automatic Initialization and Updating for TIMESTAMP
Obviously, in this case the table is called products and you would need to change it to whatever your table name is.
UPDATE
To update all existing records at the same time, just run:
UPDATE `products` SET `created` = NOW()
If you want to be more specific use:
UPDATE `products` SET `created` = NOW() WHERE `created` = '0000-00-00 00:00:00'
Method1 : Pass the Current DateTime as parameter to the Insert
Method2: Set the default value for the date time column in Product table
This seems like a really simple one but I'm struggling to figure it out. I want a column in my database that lists when a record was first created and another column that says when it was updated. It's my understanding I should be able to do all this just using MySQL. All help is appreciated :)
This stinks still no answer, reasons I'm already starting to miss Ruby on Rails...
You will probably need to use a combination of the Datetime datatype and the Timestamp data type. I would set my created column as a DateTime with a DEFAULT NOW(), and my updated column as a Timestamp with DEFAULT CURRENT_TIMESTAMP and an ON UPDATE CURRENT_TIMESTAMP attribute.
Here are the docs for the Timestamp dt:
http://dev.mysql.com/doc/refman/5.0/en/timestamp.html
In a CREATE TABLE statement, the first TIMESTAMP column can be declared in any of the following ways:
With both DEFAULT CURRENT_TIMESTAMP and ON UPDATE CURRENT_TIMESTAMP clauses, the column has the current timestamp for its default value, and is automatically updated.
With neither DEFAULT nor ON UPDATE clauses, it is the same as DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP.
With a DEFAULT CURRENT_TIMESTAMP clause and no ON UPDATE clause, the column has the current timestamp for its default value but is not automatically updated.
With no DEFAULT clause and with an ON UPDATE CURRENT_TIMESTAMP clause, the column has a default of 0 and is automatically updated.
With a constant DEFAULT value, the column has the given default and is not automatically initialized to the current timestamp. If the column also has an ON UPDATE CURRENT_TIMESTAMP clause, it is automatically updated; otherwise, it has a constant default and is not automatically updated.
To fulfill your question and for others viewing this question, here is the answer. Note this was written for MySQL 5.x.
DROP TABLE IF EXISTS `test1`;
CREATE TABLE `test1` (
`id` INT NULL AUTO_INCREMENT ,
`name` varchar(50) NOT NULL ,
`created` DATETIME ,
`updated` DATETIME ,
PRIMARY KEY (`id`),
INDEX (`name`)
);
DELIMITER $$
DROP TRIGGER IF EXISTS `test1_created`$$
CREATE TRIGGER `test1_created` BEFORE INSERT ON `test1`
FOR EACH ROW BEGIN
SET NEW.`created` = UTC_TIMESTAMP();
SET NEW.`updated` = UTC_TIMESTAMP();
END;
$$
DROP TRIGGER IF EXISTS `test1_updated`$$
CREATE TRIGGER `test1_updated` BEFORE UPDATE ON `test1`
FOR EACH ROW BEGIN
SET NEW.`updated` = UTC_TIMESTAMP();
END;
$$
DELIMITER ;
Note
You could use TIMESTAMP for the updated column which would have automatically updated the value thus not requiring the BEFORE UPDATE trigger, however TIMESTAMP has a range from 1970 to 2038 which is fast approaching and I like to think my applications will live forever :). Although TIMESTAMP is only 4bytes while DATETIME is 8bytes.
TIMESTAMP range '1970-01-01 00:00:01' UTC to '2038-01-19 03:14:07' UTC
DATETIME range '1000-01-01 00:00:00' to '9999-12-31 23:59:59'
From the MySQL 5.0 Certification Guide:
CREATE TABLE ts_test5 (
created TIMESTAMP DEFAULT 0,
updated TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
data CHAR(30)
);
To control the initialization and update behaviour of a TIMESTAMP column, you add either or both of the DEFAULT CURRENT_TIMESTAMP and ON UPDATE CURRENT_TIMESTAMP attributes to the column defintion when creating the table with CREATE TABLE...
and
...if you do not specify either of the DEFAULT CURRENT_TIMESTAMP or ON UPDATE CURRENT_TIMESTAMP attributes when creating a table, MySQL automatically assigns BOTH to the first TIMESTAMP column
Also
you cannot use DEFAULT CURRENT_TIMESTAMP with one column and ON UPDATE CURRENT_TIMESTAMP with another
If you can't use the timestamp fields with default attributes that Paul W has suggested, you can use AFTER INSERT and AFTER UPDATE triggers to populate the fields.
You will need two fields "Created" and
"Updated" with type datetime. When a
new entry is inserted then insert
"Created" with current time stamp.
When a update is happening insert
"Updated" with the current time stamp,
and let the "Created" field remain as
it is.
For current time stamp you can use
NOW() in your mysql query.
i have a table that looks like this:
Field: msg_sent_datetime
Type: datetime
yet when i use NOW() in a php mysql insert query it is staying as all zeros?
any idea why?
If you're using it only at the time of INSERT, you could make the field a TIMESTAMP and set a default of CURRENT_TIMESTAMP.
Without knowing more about the code it's difficult to suggest much else.
Example with CURRENT_TIMESTAMP
CREATE TABLE example (
id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
msg TEXT,
msg_sent_datetime TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);
Also, if you want it to always update when there's a change to the row, you can add the ON UPDATE CURRENT_TIMESTAMP property to the table definition:
CREATE TABLE example (
id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
msg TEXT,
msg_sent_datetime TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
);
Of course, all of this is totally dependent on switching to TIMESTAMP which you may not want
I dont knw exactly why, but mysql has 2 datetime functions: now() and sysdate(). Perhaps you can substitute now() with sysdate() to help you troubleshoot.
http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html#function_sysdate
Here is the table of interest when exported via phpMyAdmin:
CREATE TABLE IF NOT EXISTS `users` (
`ip` varchar(20) NOT NULL,
`lastcheck` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
UNIQUE KEY `ip` (`ip`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1;
Here is the query:
mysql_query("REPLACE INTO users SET ip = '$uip', lastcheck = '$tim'") or throwerror("part2 ".mysql_error());
$tim is set to be time();
Now for some reason lastcheck is still set as 0000-00-00 00:00:00.
Can anyone help? Thanks.
I am not sure if maybe I understand your problem, looking at column lastcheck declaration CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP that means when ever you update (ip = '$uip') this column an automatic date update will also happen lastcheck. Which mean you can write you update statment as follows :
REPLACE INTO users SET ip = '$uip';
That should also update the lastcheck field, and I think it's better to use the mysql date functions to store your date/time than writing them in php and saving them as string in the database...
try using date('Y-m-d H:i:s') in stead of time()
time() in php returns a unix timestamp and that isn't a valid insert for MyySQL datetime
hope this helps