my problem is that i have a field in novels table timestamp,on update
CURRENT_TIMESTAMP,no,CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP.
I am using CURRENT_TIMESTAMP at the time of inserting into sql but I noticed that value of all my posts showing 21-02-2014. Any help?
ON UPDATE CURRENT_TIMESTAMP means that CURRENT_TIMESTAMP fields updates when the values of that field change, not when they stay same (OR) not when you update some other field(s) other than the timestamp field and this behavior is by design.
probably you can do something like this to update it
UPDATE <your_table>
SET <your_current_timestamp> = null,
WHERE <some_condition>
Related
I am pretty new with DB and I have the following problem trying to update a Date field into a table definied on an Oracle DB.
So in my DB I have a table named CERTIFICAZIONI that have a Date field named DATA_VISUALIZZAZIONE.
I have to create a query that update the DATA_VISUALIZZAZIONE with the current date time.
So I am trying to do something like this:
UPDATE certificazione SET data_visualizzazione=??? WHERE ID=1
I think that the main structure of the query is right but I don't know how to set the current date time to this field. How can I do this?
Tnx
use systimestamp or sysdate for this based on your need, like below
UPDATE certificazione SET data_visualizzazione=systimestamp WHERE ID=1;
or
UPDATE certificazione SET data_visualizzazione=sysdate WHERE ID=1
will make the give such details about date,time and timezone.
Given that the data type is DATE, you could set the column with SYSDATE value. It will have both date and time portions.
UPDATE certificazione
SET data_visualizzazione = SYSDATE
WHERE id = 1;
I am using MS SQL Server 2008 and I have an sql table with some data that is inserted daily at 6 am by an sql job. The problem I have is that some data has been inserted separately into the job and I need to know when this data was added.
Is there a query I can run that will show me this?
I think the short answer is NO, there's no magic, ad hoc SQL query that will let you go back after the fact and find out when a row was inserted.
If you want to know when a row is inserted, the easiest thing would be to simply add a date or timestamp field with a default value (like getDate()) that automatically fills in the date/time when the row is inserted.
There are, of course, SQL logs available that will let you track when rows are inserted, updated, deleted, etc., but those require set up and maintenance.
Third option would be to have the program that's inserting the data perform some logging.
Add a date field to the table. You can give it a default value of GETDATE()
Then ORDER BY that field.
SELECT Column1, Column2, NewDateColumn
FROM YourTable
ORDER BY NewDateColumn
what i would do is :
/* add new column to keep inserted row date */
ALTER TABLE [schemaName].[tableName] ADD [RecTime] DATETIME;
/* update the existing rows with the current date since there is no way to guess their insertion date */
UPDATE [schemaName].[tableName] SET [RecTime] = GETDATE();
/* and set a constraint to the RecTime column to set current date on every new row added */
ALTER TABLE [schemaName].[tableName] ADD CONSTRAINT [DF_tableName_RecTime] DEFAULT (GETDATE()) FOR [RecTime]
then you can get those rows like :
SELECT *
FROM [schemaName].[tableName]
WHERE NOT(DATEPART(hh, RecTime) = 6 AND DATEPART(mi, RecTime) <= 20)
you can 'play' with '20' if you know how long sql job run
you probably need to look at SQL CREATE TRIGGER to add the logic to know when the data is being added and log that info in another table for further actions. Without further details I am not sure we can say more than that.
As you're referring to data which has already been inserted, the answer is No, unless you already have a datetime column which has a default value of GETDATE(). The best you can manage after the event has occurred is to look at the sequence of rows and determine that it was between two known times.
I have a TIMESTAMP(6) field in Oracle db. Value of this field is in format
DD/MM/YYYY HH:MM:SS.000000000 PM
How to update this value to the current timestamp?
[a link to a similar question:] update date value in oracle
I followed this link, but following query is taking very long time to execute.
update table_name set start_time = to_char(to_date(start_time, 'yyyy/mm/dd-hh:mi:ss:ff3'), '2012/10/10-19:30:00:00') where column='Q'
A timestamp is a point in time, it has no format. To update such a field to the current timestamp, use SYSTIMESTAMP or CURRENT_TIMESTAMP (respectively the date/time of the server and the date/time of the session):
UPDATE your_table
SET your_column = systimestamp
WHERE ...
If the query takes an abnormal amount of time (much longer than a comparable SELECT with the same WHERE clause), the mostly likely causes are:
The rows that your are updating are locked by another session (doing a SELECT FOR UPDATE NOWAIT on these rows will make sure that you have the lock).
You have triggers that perform additional work,
You're updating a column referenced by a non-indexed foreign key.
Why you don't just
update table_name
set start_date = systimestamp
where column='Q'
If you suspect there are locks on the table, there are some tables to check: dba_locks, v$session, v$session_blockers etc. These are useful when a user blocked something with an accidental update without a commit or rollback, but you should be able to see if can exists blocking locks from the architecture of your application. You should just simulate on paper all the scenarios.
Is it possible to get last updated time and date of the row using MYSQL server.
Well there is no inbuild feature exists with MySQL. Though you can get the same effect by adding a timestamp column:
ALTER TABLE NAMEYOURTABLE
ADD COLUMN last_update TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
using above to create timestamp with name last_update column will make it pretty much automatically managed and updated. Now you can select from NAMEYOURTABLE the last updated row based on the timestamp.
Is there some way mysql can store timestamp automatically in a record row whenever that it is created. I was trying to use timestamp(data type) with current_timestamp as default value but then realised this will get updated everytime the record is updated. I just need something that will store create timestamp.
Thanks
Set the DEFAULT constraint to use CURRENT_TIMESTAMP:
CREATE TABLE ...
your_date_column DATETIME DEFAULT CURRENT_TIMESTAMP
...
For an existing table, use the ALTER TABLE statement:
ALTER TABLE your_table
ALTER COLUMN date_column SET DEFAULT CURRENT_TIMESTAMP
Unless you specify a value to for the date_column, the default will be the date & time the INSERT statement was run. NULL and DEFAULT or valid values to use the default constraint otherwise, assuming the column is nullable.
You can get the full details on timestamps in MySQL at https://dev.mysql.com/doc/refman/5.0/en/timestamp-initialization.html.
The point that you care about is that if you define a timestamp column as DEFAULT CURRENT_TIMESTAMP clause and don't have an ON UPDATE clause, the column has the current timestamp for its default value but is not automatically updated.
But be warned. The obvious thing to want to do is to have two timestamp columns, one being the creation time and the other being the last update time. Unfortunately it is a documented MySQL limitation that MySQL does not support this. I have no idea why MySQL has such an odd limitation - no other major database has problems with this common use case.
FYI = "Datetime" is date and time fixed. "Timestamp" is variable date and time-- system time.
So, Have two columns. One Create Col, One Update Col.
The following command will create a hello table
1. id integer
2. create_at with current time.
create table hello (id int, created_at datetime DEFAULT CURRENT_TIMESTAMP);
Create Table myTableName
(
userId int primary key
userJoiningDate TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);
https://www.mysqltutorial.org/mysql-timestamp.aspx
Here is how you can create a column in which the time stamp is recorded when it is created. If you want to know How to update timeStamp each time that row is changed/updated, Check the above link.
SELECT * FROM test WHERE timestamp >= CURDATE() AND timestamp < CURDATE() + INTERVAL 1 DAY ORDER BY timestamp;