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why do i get invalid default value error for the variable "last_updated"?
note i am getting this error while i run the following code in MySQL console in phpmyadmin
CREATE TABLE IF NOT EXISTS `articles` (
`article_id` int(10) NOT NULL AUTO_INCREMENT,
`content_id` int(10) NOT NULL,
`article_body` text NOT NULL,
`last_updated` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP,
PRIMARY KEY (`article_id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=532 ;
You need to change the last_updated column's data type to timestamp rather than datetime. This will allow the use of CURRENT_TIMESTAMP as a default value.
As it happens, these two data types are represented in the same format YYYY-MM-DD HH:MM:SS. So if/when you use the data, you shouldn't run into any troubles.
Check your MySQL server version, CURRENT_TIMESTAMP is allowed since version 5.6.5 as DEFAULT for DATETIME type, otherwise you should use either TIMESTAMP type or maintain it outside.
I have two columns in table users namely registerDate and lastVisitDate which consist of datetime data type. I would like to do the following.
Set registerDate defaults value to MySQL NOW()
Set lastVisitDate default value to 0000-00-00 00:00:00 Instead of null which it uses by default.
Because the table already exists and has existing records, I would like to use Modify table. I've tried using the two piece of code below, but neither works.
ALTER TABLE users MODIFY registerDate datetime DEFAULT NOW()
ALTER TABLE users MODIFY registerDate datetime DEFAULT CURRENT_TIMESTAMP;
It gives me Error : ERROR 1067 (42000): Invalid default value for 'registerDate'
Is it possible for me to set the default datetime value to NOW() in MySQL?
As of MySQL 5.6.5, you can use the DATETIME type with a dynamic default value:
CREATE TABLE foo (
creation_time DATETIME DEFAULT CURRENT_TIMESTAMP,
modification_time DATETIME ON UPDATE CURRENT_TIMESTAMP
)
Or even combine both rules:
modification_time DATETIME DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
Reference:
http://dev.mysql.com/doc/refman/5.7/en/timestamp-initialization.html
http://optimize-this.blogspot.com/2012/04/datetime-default-now-finally-available.html
Prior to 5.6.5, you need to use the TIMESTAMP data type, which automatically updates whenever the record is modified. Unfortunately, however, only one auto-updated TIMESTAMP field can exist per table.
CREATE TABLE mytable (
mydate TIMESTAMP
)
See: http://dev.mysql.com/doc/refman/5.1/en/create-table.html
If you want to prevent MySQL from updating the timestamp value on UPDATE (so that it only triggers on INSERT) you can change the definition to:
CREATE TABLE mytable (
mydate TIMESTAMP DEFAULT CURRENT_TIMESTAMP
)
I use a trigger as a workaround to set a datetime field to NOW() for new inserts:
CREATE TRIGGER `triggername` BEFORE INSERT ON `tablename`
FOR EACH ROW
SET NEW.datetimefield = NOW()
it should work for updates too
Answers by Johan & Leonardo involve converting to a timestamp field. Although this is probably ok for the use case presented in the question (storing RegisterDate and LastVisitDate), it is not a universal solution. See datetime vs timestamp question.
My solution
ALTER TABLE `table_name` MODIFY COLUMN `column_name` TIMESTAMP NOT
NULL DEFAULT CURRENT_TIMESTAMP;
EUREKA !!!
For all those who lost heart trying to set a default DATETIME value in MySQL, I know exactly how you feel/felt. So here it is:
`ALTER TABLE `table_name` CHANGE `column_name` DATETIME NOT NULL DEFAULT 0
Carefully observe that I haven't added single quotes/double quotes around the 0.
Important update:
This answer was posted long back. Back then, it worked on my (probably latest) installation of MySQL and I felt like sharing it. Please read the comments below before you decide to use this solution now.
On versions mysql 5.6.5 and newer, you can use precise datetimes and set default values as well. There is a subtle bit though, which is to pass in the precision value to both the datetime and the NOW() function call.
This Example Works:
ALTER TABLE my_table MODIFY created datetime(6) NOT NULL DEFAULT NOW(6);
This Example Does not Work:
ALTER TABLE my_table MODIFY created datetime(6) NOT NULL DEFAULT NOW();
mysql 5.6 docs say that CURRENT_TIMESTAMP can be used as default for both TIMESTAMP and DATETIME data types:
http://dev.mysql.com/doc/refman/5.6/en/timestamp-initialization.html
`ALTER TABLE `table_name` CHANGE `column_name`
timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP
ON UPDATE CURRENT_TIMESTAMP
Can be used to update the timestamp on update.
The best way is using "DEFAULT 0".
Other way:
/************ ROLE ************/
drop table if exists `role`;
create table `role` (
`id_role` bigint(20) unsigned not null auto_increment,
`date_created` datetime,
`date_deleted` datetime,
`name` varchar(35) not null,
`description` text,
primary key (`id_role`)
) comment='';
drop trigger if exists `role_date_created`;
create trigger `role_date_created` before insert
on `role`
for each row
set new.`date_created` = now();
This worked for me, using MySQL:
ALTER TABLE `table_name` MODIFY `column_name` datetime NOT NULL DEFAULT NOW();
ALTER TABLE table_name
CHANGE COLUMN date_column_name date_column_name DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP;
Finally, This worked for me!
CREATE TABLE `users` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`dateCreated` datetime DEFAULT CURRENT_TIMESTAMP,
`dateUpdated` datetime DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
PRIMARY KEY (`id`),
UNIQUE KEY `mobile_UNIQUE` (`mobile`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
Not sure if this is still active but here goes.
Regarding setting the defaults to Now(), I don't see that to be possible for the DATETIME data type. If you want to use that data type, set the date when you perform the insert like this:
INSERT INTO Yourtable (Field1, YourDateField) VALUES('val1', (select now()))
My version of mySQL is 5.5
This worked for me - just changed INSERT to UPDATE for my table.
INSERT INTO Yourtable (Field1, YourDateField) VALUES('val1', (select now()))
I have this table:
CREATE TABLE IF NOT EXISTS news (
id int(11) NOT NULL AUTO_INCREMENT,
data text,
date_published timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
date_edited timestamp NULL DEFAULT NULL ON UPDATE CURRENT_TIMESTAMP,
PRIMARY KEY (id)
);
Giving me this error:
#1293 - Incorrect table definition; there can be only one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause.
There are older posts regarding this problem, but i want a proper workaround, due to current database structure.
Version: libmysql - 5.5.41
Running on: 5.5.41-ubuntu.14.04.1
It's a hard limitation. Best bet is making date_edited use CURRENT_TIMESTAMP and managing date_published in your application.
date_published timestamp NULL DEFAULT NULL,
date_edited timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
Triggers might be an alternative option, but I try not to rely on stuff like that that can't easily be version-controlled.
I have two columns in table users namely registerDate and lastVisitDate which consist of datetime data type. I would like to do the following.
Set registerDate defaults value to MySQL NOW()
Set lastVisitDate default value to 0000-00-00 00:00:00 Instead of null which it uses by default.
Because the table already exists and has existing records, I would like to use Modify table. I've tried using the two piece of code below, but neither works.
ALTER TABLE users MODIFY registerDate datetime DEFAULT NOW()
ALTER TABLE users MODIFY registerDate datetime DEFAULT CURRENT_TIMESTAMP;
It gives me Error : ERROR 1067 (42000): Invalid default value for 'registerDate'
Is it possible for me to set the default datetime value to NOW() in MySQL?
As of MySQL 5.6.5, you can use the DATETIME type with a dynamic default value:
CREATE TABLE foo (
creation_time DATETIME DEFAULT CURRENT_TIMESTAMP,
modification_time DATETIME ON UPDATE CURRENT_TIMESTAMP
)
Or even combine both rules:
modification_time DATETIME DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
Reference:
http://dev.mysql.com/doc/refman/5.7/en/timestamp-initialization.html
http://optimize-this.blogspot.com/2012/04/datetime-default-now-finally-available.html
Prior to 5.6.5, you need to use the TIMESTAMP data type, which automatically updates whenever the record is modified. Unfortunately, however, only one auto-updated TIMESTAMP field can exist per table.
CREATE TABLE mytable (
mydate TIMESTAMP
)
See: http://dev.mysql.com/doc/refman/5.1/en/create-table.html
If you want to prevent MySQL from updating the timestamp value on UPDATE (so that it only triggers on INSERT) you can change the definition to:
CREATE TABLE mytable (
mydate TIMESTAMP DEFAULT CURRENT_TIMESTAMP
)
I use a trigger as a workaround to set a datetime field to NOW() for new inserts:
CREATE TRIGGER `triggername` BEFORE INSERT ON `tablename`
FOR EACH ROW
SET NEW.datetimefield = NOW()
it should work for updates too
Answers by Johan & Leonardo involve converting to a timestamp field. Although this is probably ok for the use case presented in the question (storing RegisterDate and LastVisitDate), it is not a universal solution. See datetime vs timestamp question.
My solution
ALTER TABLE `table_name` MODIFY COLUMN `column_name` TIMESTAMP NOT
NULL DEFAULT CURRENT_TIMESTAMP;
EUREKA !!!
For all those who lost heart trying to set a default DATETIME value in MySQL, I know exactly how you feel/felt. So here it is:
`ALTER TABLE `table_name` CHANGE `column_name` DATETIME NOT NULL DEFAULT 0
Carefully observe that I haven't added single quotes/double quotes around the 0.
Important update:
This answer was posted long back. Back then, it worked on my (probably latest) installation of MySQL and I felt like sharing it. Please read the comments below before you decide to use this solution now.
On versions mysql 5.6.5 and newer, you can use precise datetimes and set default values as well. There is a subtle bit though, which is to pass in the precision value to both the datetime and the NOW() function call.
This Example Works:
ALTER TABLE my_table MODIFY created datetime(6) NOT NULL DEFAULT NOW(6);
This Example Does not Work:
ALTER TABLE my_table MODIFY created datetime(6) NOT NULL DEFAULT NOW();
mysql 5.6 docs say that CURRENT_TIMESTAMP can be used as default for both TIMESTAMP and DATETIME data types:
http://dev.mysql.com/doc/refman/5.6/en/timestamp-initialization.html
`ALTER TABLE `table_name` CHANGE `column_name`
timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP
ON UPDATE CURRENT_TIMESTAMP
Can be used to update the timestamp on update.
The best way is using "DEFAULT 0".
Other way:
/************ ROLE ************/
drop table if exists `role`;
create table `role` (
`id_role` bigint(20) unsigned not null auto_increment,
`date_created` datetime,
`date_deleted` datetime,
`name` varchar(35) not null,
`description` text,
primary key (`id_role`)
) comment='';
drop trigger if exists `role_date_created`;
create trigger `role_date_created` before insert
on `role`
for each row
set new.`date_created` = now();
This worked for me, using MySQL:
ALTER TABLE `table_name` MODIFY `column_name` datetime NOT NULL DEFAULT NOW();
ALTER TABLE table_name
CHANGE COLUMN date_column_name date_column_name DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP;
Finally, This worked for me!
CREATE TABLE `users` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`dateCreated` datetime DEFAULT CURRENT_TIMESTAMP,
`dateUpdated` datetime DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
PRIMARY KEY (`id`),
UNIQUE KEY `mobile_UNIQUE` (`mobile`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
Not sure if this is still active but here goes.
Regarding setting the defaults to Now(), I don't see that to be possible for the DATETIME data type. If you want to use that data type, set the date when you perform the insert like this:
INSERT INTO Yourtable (Field1, YourDateField) VALUES('val1', (select now()))
My version of mySQL is 5.5
This worked for me - just changed INSERT to UPDATE for my table.
INSERT INTO Yourtable (Field1, YourDateField) VALUES('val1', (select now()))
I've got a table that looks like this:
CREATE TABLE IF NOT EXISTS `Hosts` (
`id` int(128) NOT NULL AUTO_INCREMENT,
`IP` varchar(15) NOT NULL DEFAULT '',
`Port` varchar(5) NOT NULL DEFAULT '',
`Password` varchar(32) NOT NULL DEFAULT '',
`Username` varchar(32) NOT NULL DEFAULT '',
`Tid` varchar(32) NOT NULL DEFAULT '',
`EquipType` varchar(64) NOT NULL DEFAULT '',
`Version` varchar(128) DEFAULT NULL,
`Status` varchar(10) NOT NULL DEFAULT '',
`Location` varchar(128) NOT NULL DEFAULT '',
`Lastconnection` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00' ON UPDATE CURRENT_TIMESTAMP,
`Lastbackup` date NOT NULL DEFAULT '0000-00-00',
`Backupstatus` varchar(64) NOT NULL DEFAULT '',
`Backupmsg` text,
`Backupfile` varchar(30) NOT NULL DEFAULT '',
PRIMARY KEY (`id`),
KEY `IP` (`IP`),
KEY `Tid` (`Tid`),
KEY `EquipType` (`EquipType`),
KEY `Status` (`Status`),
KEY `Lastbackup` (`Lastbackup`),
KEY `Backupstatus` (`Backupstatus`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=716 ;
In my mind, this means that any time a row is updated, the field 'Lastconnection' should be stamped with the current timestamp. However, when I run something like:
update Hosts set Backupstatus = 'FAIL', Backupmsg = 'Connection timed out' where Tid = 'SITE001'
Lastconnection stays '0000-00-00 00:00:00'. There's either a database issue I'm not seeing, or I'm completely misunderstanding the 'ON UPDATE CURRENT_TIMESTAMP' clause.
Have you tried to use null for that field when updating?
You could also try setting default value to CURRENT_TIMESTAMP, rather than 0000-00-00 00:00:00.
Nevertheless, whenever I want to have creation and update time I always use the following:
...
CREATED timestamp NOT NULL default '0000-00-00 00:00:00',
UPDATED timestamp NOT NULL default now() on update now(),
....
I use now(), because is an alias for CURRENT_TIMESTAMP and it is shorter. At the end, table structure gets CURRENT_TIMESTAMP, so don't worry.
The trick with CREATED field is to remember to use null on both fields for INSERT statements, for UPDATE statements it is not required:
INSERT INTO mytable (field1, field2, created, updated)
VALUES ('foo', 'bar', null, null);
It might be the case that the update statement doesn't change anything. If the row with Tid = 'SITE001' already has Backupstatus set to 'FAIL' and Backupmsg set to 'Connection timed out' (maybe, set by some previous backup attempt), then MySQL will skip this row and therefore won't change the Lastconnection timestamp.
Also, I see ON UPDATE CURRENT_TIMESTAMP more like an administrative feature to keep track of data changes. As a programmer, I would add the timestamp update explicitly:
update Hosts
set Backupstatus = 'FAIL', Backupmsg = 'Connection timed out', Lastconnection = NOW()
where Tid = 'SITE001'.
You must remember that if no value was changed on update it won't set the current time stamp,
You have to set the value in query NOW() to set for the current time stamp !!!
update Hosts set Backupstatus = 'FAIL',Lastconnection = NOW() , Backupmsg = 'Connection timed out' where Tid = 'SITE001'
Remember the value must change in order for the current time stamp to change.
To specify automatic properties, use the DEFAULT CURRENT_TIMESTAMP and ON UPDATE CURRENT_TIMESTAMP clauses. The order of the clauses does not matter. If both are present in a column definition, either can occur first. Any of the synonyms for CURRENT_TIMESTAMP have the same meaning as CURRENT_TIMESTAMP. These are CURRENT_TIMESTAMP(), NOW(), LOCALTIME, LOCALTIME(), LOCALTIMESTAMP, and LOCALTIMESTAMP().
Use of DEFAULT CURRENT_TIMESTAMP and ON UPDATE CURRENT_TIMESTAMP is specific to TIMESTAMP. The DEFAULT clause also can be used to specify a constant (nonautomatic) default value; for example, DEFAULT 0 or DEFAULT '2000-01-01 00:00:00'.
DEFAULT 0 do not work if the NO_ZERO_DATE SQL mode is enabled because that mode causes “zero” date values (specified, for example, as 0 '0000-00-00 00:00:00') to be rejected. Be aware that the TRADITIONAL SQL mode includes NO_ZERO_DATE.
In addition, you can initialize or update any TIMESTAMP column to the current date and time by assigning it a NULL value, unless it has been defined with the NULL attribute to permit NULL values.
If you want the record to automatically update the timestamp whenever the record is changed, here's the four simple steps you need to accomplish (could be all in one step, depending on if you're using command line or GUI to administer):
Create field to hold auto-updated timestamp (I typically call mine 'modified').
Specify field Type as 'TIMESTAMP'
Specify field Default as 'CURRENT_TIMESTAMP'
Specify field Extra as 'ON UPDATE CURRENT_TIMESTAMP'
Now the field that contains your timestamp will always be updated to the current timestamp anytime the record is updated.