At present I have a column with datatype datetime with default constraint. Now I want to alter as a data type as time stamp.
alter table tblname
alter column date_modified timestamp not null
My original requirement is whenever I update a record the column called date_modified should update with recent time .
This is same functionality which is working in MYSQL with datatype TIMESTAMP and default value CURRENT_TIMESTAMP
How can I perform in this in SQL Server 2008??
Timestamp in MySQL and timestamp in SQL Server is not the same thing. Keep your datetimeand add an after update trigger that updates date_modified with getdate().
Did you check what the TIMESTAMP type actually is in SQL Server? It's different from the TIMESTAMP type in mysql. The documentation says:
Is a data type that exposes automatically generated, unique binary numbers within a database
So there's no way to set it to "the current time"
Related
I'm using Visual Studio connected to my SQL Server to create a new database and populate a table with some mock data for application development testing. I created a table with 5 fields, an auto-increment PK, three nvarchar(50) fields and a date. When I view the table data and attempt to add a row, it doesn't allow me to type into the Date field nor give me any way to insert a date into the field. How can I accomplish this?
I was not descriptive enough and it turns out it was a confusion between a timestamp and a datetime datatype. I was trying to use timestamp thinking when I did an insert it would give the CURRENT_TIMESTAMP. As it turns out the timestamp is really rowversion and has nothing to do with an actual datetime. I have since changed the datatype to datetime and have had no problems.
I have a table with a column where it gets updated with todays date when the SSIS package complete. But the thing is I need to capture the time and date at which the column gets updated to todays date into another table with help of trigger
Just add a SQL Server TRIGGER to update the timestamp after update to your "key" column. Making the timestamp column have a default of "getdate()" will handle the inserts.
Is there any way to update the modified date time automatically in SQL Server.
I do not want to use Triggers. Also I want to avoid providing the value through application while calling SQL query.
Is there any support in SQL or in Dapper etc.
If you want to keep track of the changes in database you can use a feature called
System-Versioned Temporal Table as explained here.
Using a Temporal Table, you will be able to query the recent state of the row as usual, in addition to the ability to query the full history of that row
It's very handy if you are interested in keeping a history of data changes
I am able to solve the problem using Temporal Table. I am not sure is this a elegant solution. Here is how i solved.
Create Table:
CREATE TABLE extable4 (PriKey int PRIMARY KEY, ColValue varchar(200)
, [ModifiedDateTime] datetime2 (2) GENERATED ALWAYS AS ROW START
, [ModifiedExpiryDateTime] datetime2 (2) GENERATED ALWAYS AS ROW END HIDDEN
, PERIOD FOR SYSTEM_TIME (ModifiedDateTime,[ModifiedExpiryDateTime])
) ;
Insert a record with out providing input to ModifiedDatetime.
insert into extable4(PriKey,ColValue) values(1,'Ver 1');
ModifiedDateTime Populated with systime.
update extable4 set ColValue='Ver 1.1' where PriKey=1;
ModifiedDateTime updated now. :)
I need to create a table in SQL Server 2000.
create table TABLE (
DBID_ bigint not null,
CLASS_ varchar(255) not null,
DBVERSION_ integer not null,
HPROCI_ bigint,
TYPE_ varchar(255),
EXECUTION_ varchar(255),
ACTIVITY_NAME_ varchar(255),
START_ timestamp,
END_ timestamp,
DURATION_ bigint,
TRANSITION_ varchar(255),
NEXTIDX_ integer,
HTASK_ bigint,
primary key (DBID_)
);
An error occurs when I run it.
A table can only have one timestamp column. Because table TABLE
already has one, the column END_ cannot be added.
What is the best alternative for timestamp for SQL Server? How to fix this issue?
A timestamp is not a datetime datatype as the name suggests. It is an internal value that is relative to the server's clock, but an actual time cannot be derived from it's value. It is simply used to evaluate whether a row has been updated, and thus a table can only have one column of this type. The timestamp syntax is actually deprecated and is now named rowversion which makes a lot more sense.
Given your column names (Start, End) I assume you are trying to store actual timestamps, and should instead be using datetime as your datatype.
In Sql Server timestamp is a data type and it's not a time.
It's basically a way of versioning a record and it's used for optimistic locking in a disconnected database model
When you load up the record, you pick up the timestamp column. You only write it back if the value in the timestamp column is the same, as that means no one else has changed it since you got it.
If you want a real datetime value, add a datetime either not null, or with a default of GetDate() and remember to update every update.
I have a time stamp field in a table and I've unticked the box in designer for allowing Nulls
I'm unable to enter anything in default value and binding field ( this is greyed out and doesn't allow you type anything )
I'm trying all my sql experiments out in the query designer of sql server express 2008
If I Insert a new record into the table the timestamp field gives a value that looks like:
0x00000000000007D7
As you can see this is totally unreadable:
How can I get round this/ get a readable time stamp in there?
Use DATETIME with a default constraint of GETDATE
You can do that like this:
CREATE TABLE myTable
(
ID INT IDENTITY(1,1) PRIMARY KEY CLUSTERED,
myTimeStamp datetime NOT NULL DEFAULT GETDATE()
)
TIMESTAMP is a binary field used for row versioning and cannot be edited.
From BOL:
timestamp is a data type that exposes automatically generated binary numbers, which are guaranteed to be unique within a database.
timestamp is used typically as a mechanism for version-stamping table
rows. The storage size is 8 bytes.