I am working on MySql and I have to set the time-stamp of the one of the field of my column to be 4 days ahead from current time-stamp. I created the triggers for the same.
My timestamp fields are Insert_Time and Bid_Time with Default value set as Current_Timestamp.
My Trigger Query:
CREATE TRIGGER setDefaultDate BEFORE INSERT ON product FOR EACH ROW SET New.Bid_Time = ADDDATE(curdate(), INTERVAL 4 DAY);
I tried inserting the rows into table but trigger seems not working. In both the fields I can see the current timestamp only.
My Insert Query:
insert into test.product (ITEM_NAME,ITEM_DESC,Item_Price, ITEM_QTY,SELLER_FIRSTNAME, SELLER_LASTNAME,EMAIL,SELLER_USERNAME,CATEGORY,GROUP_NAME,Bid,COND ) values ('J.K Rowling','HARRYPOTTER AND MYSTERY ','60','10','sahil','kaw', 'sahil1.kaw#gmail.com', 'sahraw','BOOKS','FICTION','1','NEW');
Is it because I am not providing the timestamp value while inserting.
Please find the screen-print attached for the schema of the tables.
This is mostly speculation, but I'm pretty sure the problem is the fact that bid_time has a default value of timestamp. Such columns are automatically initialized.
Unfortunately, the copious documentation on the subject does not seem to address triggers. However, I could easily imagine that the automatic value over-rides the trigger.
Related
I am using MySql and I have a field of type `BIGINT(20).
I realise that I can use CURRENT_TIMESTAMP as default as explained here.
However, how do I assign, by default, a javascript-like timestamp, which includes milliseconds?
I am happy to just have the "000" at the end if there is no other way to have a millisecond-precise timestamp.
UPDATE: Please note that the question is based on leaving the column type as BIGINT(20)
The basic answer to your question is you can't, as BIGINT columns can not have CURRENT_TIMESTAMP as a default value.
If you change your column type to TIMESTAMP(3) it will record timestamps with 3 decimal places of precision (i.e. down to milliseconds). You can have up to 6 decimal places. See the manual. In this situation you will also want to change your default to CURRENT_TIMESTAMP(3).
Demo on dbfiddle
A workaround to make it appear as if the column is a BIGINT would be to create a VIEW on the table using UNIX_TIMESTAMP for reading e.g.
CREATE VIEW jobs_us AS
SELECT ..., UNIX_TIMESTAMP(added) AS added
FROM jobs
and use INSERT and UPDATE triggers to convert integer values to TIMESTAMP format using FROM_UNIXTIME e.g.
CREATE TRIGGER jobs_added BEFORE INSERT ON jobs
FOR EACH ROW
BEGIN
IF NEW.added IS NOT NULL THEN
SET NEW.added = FROM_UNIXTIME(NEW.added);
END IF;
END
In MySQL, I want to fire a trigger when update on all columns except one column update.
In my table row I have 40 columns. I want trigger to update the column update_time whenever there is an update happens on any field except update_time field.
CREATE TRIGGER `UpdateDateTrigger`
BEFORE UPDATE ON `users`
FOR EACH ROW
IF NOT UPDATE(`update_time`) BEGIN
SET new.update_timestamp = now()
END
But it is not working as expected.
By looking at MySQL automatic update for specific column instead of whole record , I've got the solution to exclude two columns update in trigger
IF !((NEW.last_visited <> OLD.last_visited) ||
(NEW.update_time <> OLD.update_time)) THEN
SET new.update_time = now();
END IF
Thank you!
Instead of having a trigger function I would like to suggest you to create the table wisely so that the update_time field gets updated automatically when something is changed associated with that row.
Please look into the documentation here for automatic update on time for each update of the row. The create syntax is simple and effective.
CREATE TABLE t1 (
// .... Other columns
ts TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
dt DATETIME DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
);
If you want a specific control over each of your column, then writing a trigger is the best idea I think. Please check the answer here.
I've attempted to create a trigger to update the CREATED_DATE field of my table when a new row is inserted, but it ends up breaking the Java Application.
Basically I have an NMS that is writing to the MySql server when there is an alarm. I created the following trigger because the Java application is not applying a timestamp to alarm creation (even though there is a field for it):
CREATE TRIGGER alarm_timestamp AFTER INSERT on Alarm_Details FOR EACH ROW UPDATE Alarm_Details SET CREATED_DATE = NOW() WHERE ID = NEW.ID;
After I make this trigger, the alarms never write to the table. Then I drop the trigger and they instantly work again.
Is there a problem with the way I wrote the trigger? I'm surprised a trigger in the Sql server is preventing the application from submitting an insert query.
I have now tried to add a default value to the column with the following:
alter table Alarm_Details add constraint df_alarm_time default NOW() for CREATED_DATE;
I get a syntax error though near 'default NOW() for CREATED_DATE.'
I also tried:
ALTER TABLE Alarm_Details ALTER CREATED_DATE SET DEFAULT NOW();
It doesn't like NOW, CURRENT_TIMESTAMP, or anything. The column is set to type datetime.
I am using MySql 5.5.25.
I have a MySQL table which hen created automatically puts a ISO 8601 timestamp into one of the fields. It does this because I have set the default value thought phpMyAdmin to TIMESTAMP.
When I update the field I want to add another timestamp to another field. Obviously I cant do that using the default option. Is there an SQL command to add a current timestamp to a field? I have had a quick read through the MySQL website but I couldnt find a way to do it...
I also had a look to see if there was a way of generating an ISO8601 timestamp through PHP but I couldnt figure out a way to convert from a PHP/unix timestamp to ISO8601.
Cheers!
MySQL can automatically initialise and/or update a single TIMESTAMP type column within every table to the current time on INSERT and UPDATE. As explained in Automatic Initialization and Updating for TIMESTAMP:
One TIMESTAMP column in a table can have the current timestamp as the default value for initializing the column, as the auto-update value, or both. It is not possible to have the current timestamp be the default value for one column and the auto-update value for another column.
In your case, because you want separate columns to hold the record's initialisation and update times, you will need to set one (or both) of those columns explicitly; one can explicitly set a date/time column to the current date/time in SQL using the NOW() function:
INSERT INTO my_table (created) VALUES (NOW());
UPDATE my_table SET updated = NOW();
One can even use triggers to achieve the automatic behaviour that is not natively provided by MySQL:
CREATE TRIGGER set_init_time AFTER INSERT ON my_table FOR EACH ROW
SET NEW.created = NOW();
CREATE TRIGGER set_updt_time AFTER UPDATE ON my_table FOR EACH ROW
SET NEW.updated = NOW();
Hi I would like to set and forget two fields for tracking the date the record was added and also the date the record was last modified in a mySQL database.
I am using "ON UPDATE CURRENT_TIMESTAMP" and was hoping I would just change UPDATE to INSERT.
No luck however. Can anyone give me the heads up on the best way to achieve this? - preferably inside the database itself.
This assumes MySQL 5. Simply add two triggers:
create table foo (a1 INT, created timestamp, updated timestamp) engine=innodb;
DELIMITER |
CREATE TRIGGER foo_created BEFORE INSERT ON foo
FOR EACH ROW BEGIN
SET new.created := now();
SET new.updated := now();
END;
|
CREATE TRIGGER foo_updated BEFORE UPDATE ON foo
FOR EACH ROW BEGIN
SET new.updated := now();
END;
|
DELIMITER ;
insert into foo (a1) values(7);
select * from foo;
update foo set a1=9;
You basically need both columns to be setup as timestamps with default values of CURRENT_TIMESTAMP. Unfortunately, this is not allowed in MySQL:
Error Code: 1293
Incorrect table definition; there can be only one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause
You can't have two timestamp columns, even though you need one to only have a default value of CURRENT_TIMESTAMP, and the other one to be UPDATE CURRENT_TIMESTAMP, this is still not allowed.
Your best bet here would be to specify as so:
CREATE TABLE `test` (
`addedDate` dateTime,
`lastModified` timestamp on update CURRENT_TIMESTAMP
)
Unfortunately, you'll have to set the 'addedDate' manually on insert using the NOW() function.
mySQL has a NOW() function you can use, see the tutorial at Tutorials Point that can help you put it in place.
You could add a DATETIME column and set it when you create the row of data. That will serve as the date the record was added.
Next, add a TIMESTAMP column:
Automatic updating of the first TIMESTAMP column in a table occurs under any of the following conditions:
You explicitly set the column to NULL.
The column is not specified explicitly in an INSERT or LOAD DATA INFILE statement.
The column is not specified explicitly in an UPDATE statement and some other column changes value. An UPDATE that sets a column to the value it does not cause the TIMESTAMP column to be updated; if you set a column to its current value, MySQL ignores the update for efficiency.
The TIMESTAMP column will take care of your record modified date.