How do you set a default value for a MySQL Datetime column?

Question

How do you set a default value for a MySQL Datetime column?

In SQL Server it\'s getdate(). What is the equivalant for MySQL? I\'m using MySQL 5.x if tha

Answer 1

Working fine with MySQL 8.x

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;

Answer 2

For all who use the TIMESTAMP column as a solution i want to second the following limitation from the manual:

http://dev.mysql.com/doc/refman/5.0/en/datetime.html

"The TIMESTAMP data type has a range of '1970-01-01 00:00:01' UTC to '2038-01-19 03:14:07' UTC. It has varying properties, depending on the MySQL version and the SQL mode the server is running in. These properties are described later in this section. "

So this will obviously break your software in about 28 years.

I believe the only solution on the database side is to use triggers like mentioned in other answers.

Answer 3

You can use now() to set the value of a datetime column, but keep in mind that you can't use that as a default value.

Answer 4

I think it simple in mysql since mysql the inbuilt function called now() which gives current time(time of that insert).

So your query should look like similarly

CREATE TABLE defaultforTime(
    `creation_time`     DATETIME DEFAULT CURRENT_TIMESTAMP,
    `modification_time` DATETIME default now()
);

Thank you.

Answer 5

For all those who lost heart trying to set a default DATETIME value in MySQL, I know exactly how you feel/felt. So here is 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

I'm literally jumping after solving this one :D

Answer 6

Here is how to do it on MySQL 5.1:

ALTER TABLE `table_name` CHANGE `column_name` `column_name` 
TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP;

I have no clue why you have to enter the column name twice.