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
Related
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.
Background
I have a MySQL db with around 16 million records. There are 2 columns created_at and updated_at which are presently in datetime format.
The Problem
I'd like to change this to UNIX Timestamp by converting all the values and updating the records with the new values.
I know how to do this with PHP in loops, but is there a way to perform this update by executing a single query in MySQL?
As it'll be a one time change; you can proceed this way:
Create new columns with INT datatypes and name them, say, created and updated.
ALTER TABLE `nameOfTable`
ADD COLUMN `created` INT UNSIGNED NOT NULL DEFAULT '0' AFTER `created_at`,
ADD COLUMN `updated` INT UNSIGNED NOT NULL DEFAULT '0' AFTER `updated_at`;
Update table:
UPDATE `nameOfTable`
SET `created` = UNIX_TIMESTAMP( `created_at` ),
`updated` = UNIX_TIMESTAMP( `updated_at` );
Remove the older columns and rename newer ones back to created_at and updated_at.
Alternative way:
Set the DATETIME columns to VARCHAR field.
Update using the query:
UPDATE `nameOfTable`
SET `created_at` = UNIX_TIMESTAMP( `created_at` ),
`updated_at` = UNIX_TIMESTAMP( `updated_at` );
Change the columns to INT.
hjpotter92's answer helped a lot.
But in my case it did not solve the problem right away, since the dates I had stored were in a format not accepted as an argument by UNIX_TIMESTAMP.
So I had to first convert it to an accepted format. After some research I got to the following query that made it:
UPDATE tableName set newFieldName = UNIX_TIMESTAMP(STR_TO_DATE(CAST(priorFieldName AS CHAR), '%m/%d/%y'));
I unable to update current time(NOW) in last_updated cloumn.
Because i have read this query from text file.
INSERT OR REPLACE INTO table_name (kb_corporate_guid,kb_user_guid,
name,last_updated)
VALUES ('100','121','FAQ','2013-02-07 07:06:05');
I want to ignore last_updated cloumn value '2013-02-07 07:06:05' even if i specified in query and replace with NOW() value into last_updated cloumn.
I tried this one but it won't work for me.
ALTER TABLE table_name
CHANGE `last_updated` `last_updated` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00' ON UPDATE CURRENT_TIMESTAMP;
Option 1
You may create trigger on insert/update which will update last_updated field with MySql NOW() function, it will overwrite the field value, but it might slow down the process when you do bulk insert/update.
Option 2
Find and Replace the text for last_updated field and timestamp values from text file.
Option 3
Create temporary table with same schema and import into temporary table then use INSERT INTO main_table SELECT corp_id, user_id, name, NOW() FROM temp_table table to insert into main table.
Default is used when the value is not sent in the query, use now in the query instead of timestamp..
I am working with a database that has a table called date, which contains a separate field for day, month, year. Clearly this is not ideal when I am trying to run comparisons, etc. I am wondering is it possible for me to add a DateTime field to each row of this table and insert a concatenated string into the new field from the existing day, month, year fields.
I am quite sure its possible, I'm just wondering if anyone might be able to point me in the right direction on how to achieve this?
Below is the current date table: (i know)
CREATE TABLE IF NOT EXISTS `date` (
`deposition_id` varchar(11) NOT NULL default '',
`day` int(2) default NULL,
`month` int(2) default NULL,
`year` int(4) default NULL,
PRIMARY KEY (`deposition_id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
first use alter table query:
alter table date add column datetimefield datetime NOT Null
then
use update query with self join on date and update datetimefield with concat on date,month, year column values.
Try this (untested) -
UPDATE date d SET d.datetime = (SELECT CONCAT('-','year','month','day') from date d1 where d1.id = d.id);
What is the problem, I don't understand? Alter the table, add new DATE column and then populate it with a string "yyyy-mm-dd" using CONCAT mysql function or whatever.
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.