I want to be able to have todays date and time now in a table column
If my table is say Table1, basically it should display the time and date when
SELECT * FROM Table1 is run.
I've tried the following but they just show the time from the moment in time I assign the value to column
ALTER TABLE Table1
ADD TodaysDate DateTime NOT NULL DEFAULT GETDATE()
and
ALTER TABLE Table1
ADD TodaysDate DateTime
UPDATE Table1
SET TodaysDate = GETDATE()
Hope this is clear. any help is appreciated.
Thanks
In SQL Server you can use a computed column:
alter table table1 add TodaysDate as (cast(getdate() as date));
(use just getdate() for the date and time)
This adds a "virtual" column that gets calculated every time it is referenced. The use of such a thing is unclear. Well, I could imagine that if you are exporting the data to a file or another application, then it could have some use for this to be built-in.
I hope this clarifies your requirement.
The SQL Server columns with default values stores the values inside the table. When you select the values from table, the stored date time will be displayed.
There are 2 options I see without adding the column to the table itself.
You can use SELECT *, GETDATE() as TodaysDate FROM Table1
You can create a view on top of Table 1 with additional column like
CREATE VIEW vw_Table1
AS
SELECT *, GETDATE() as TodaysDate FROM dbo.Table1
then you can query the view like you mentioned (without column list)
SELECT * FROM vw_Table1
This will give you the date and time from the moment of the execution of the query.
Related
I have three table in the database two of them contain dates however the dates are in two format, first 20-02-2011 and second is 25/09/2018. Let say each table have 10000 records and mixed with these two types of dates format. This why I why I create the column like --- (Transaction_Date, Varchar(10) Not Null)
I tried convert (Varchar(10),Transaction_Date,105)
and also tried replace(convert(varchar(10),Transaction_Date,105),'/','-')
However date and year functions are still not working.
Please suggest a possible way.
How about this?
select replace(date, replace(Transaction_Date, '/', '-'), 105)
That is: (1) convert to a date and (2) replace the slash before converting.
You need to remember about your culture. Saved format vs server culture. But this is very possible
select Cast('2-22-2011' as datetime) f1,
Cast('2/22/2011' as datetime) f2
I other words just use Cast
select cast(Transaction_Date as datetime) . . .
But you should as soon as possible get rid of columns that saves date as string and create new date/time column, and insert your date values there
alter table tbl add column temp datetime
update tbl set temp = Cast(Transaction_Date as datetime)
alter table tbl drop column Transaction_Date
alter table tbl add column Transaction_Date datetime
update tbl set Transaction_Date = temp
alter table tbl drop column temp
I'm trying to add a column called tstamp to a table that I've created. The column is to have the current timestamp in the format 'yyyy-MM-dd' populating each row.
I initially created the table from another table (table1) using the statement:
create location2.table2
as (select *
from location1.table1
);
I then used the alter table statement to add a field called tstamp to table2 using the code:
alter table location2.table2
add columns (tstamp date)
and I can see that this has successfully added a column to table2 named tstamp and populated each row of this table as null. I am now trying to insert the current date into every row in the field tstamp but am struggling to do so. I've tried using the insert into statement as:
insert into location2.table2 (tstamp)
values (to_date(current_timestamp()))
but get the error "Expression of type TOK_FUNCTION not supported in insert/values". I then also tried to add just a string and replaced the function with '2019-07-25'. Doing this added a new row to my table with null values in every column except tstamp which had a value '2019-07-25'. I'm now confused as it appears my approach was not the right one for the problem and am unsure where to go from here. Any help would be greatly appreciated.
create location2.table2 as (select current_date as tstamp,* from location1.table1 );
i am using sql server in making my project with javafx. Their i have a table of purchase and sale. One of the column of both of them is date having current date and time to store them as a record that this transaction has been saved in this time.
Now i am using the that date column with varchar datatype and have using computed column specification with following function:
(CONVERT([varchar](25),getdate(),(120)))
but when i select records from that table using query
SELECT pr.Date, p.Name, pr.Quantity, s.Name, p.Pur_Price
FROM (([Product] AS p
INNER JOIN [Purchase] AS pr ON pr.Product_id=p.Product_id)
INNER JOIN [Supplier] AS s ON s.Supplier_Id=p.Supplier_Id)
WHERE pr.Date>= dateadd(dd, 0, datediff(dd, 0, getdate()-30))
but it selects all the records keeping all date records to current date and time. Thanks in advance.
Looking forward for your good replies.
The problem is that your Date column is computed on the fly and not actually stored in the table. So each time you SELECT from that table, the expression of the computed column is calculated (CONVERT([varchar](25),getdate(),(120))) thus resulting in the same value for all rows.
A fix would be using a PERSISTED computed column so that values are actually stored with the table when inserting or updating:
CREATE TABLE Product (
OtherColumns INT,
[Date] AS (CONVERT([varchar](25), getdate(), 120)) PERSISTED)
The problem with this is that non-deterministic expressions can't be persisted, as this error message pops up:
Msg 4936, Level 16, State 1, Line 1 Computed column 'Date' in table
'Product' cannot be persisted because the column is non-deterministic.
You have several other options for this. Please use DATE or DATETIME columns to store and handle dates and avoid using VARCHAR for this as it brings many problems. The following examples use DATETIME:
Use a DEFAULT constraint linked to the column with the expression you want:
CREATE TABLE Product (
OtherColumns INT,
[Date] DATETIME DEFAULT GETDATE())
INSERT INTO Product (
OtherColumns) -- Skip the Date column on the INSERT
VALUES
(1)
SELECT * FROM Product
OtherColumns Date
1 2018-12-14 08:49:08.347
INSERT INTO Product (
OtherColumns,
Date)
VALUES
(2,
DEFAULT) -- Or use the keyword DEFAULT to use the default value
SELECT * FROM Product
OtherColumns Date
1 2018-12-14 08:49:08.347
2 2018-12-14 08:50:10.070
Use a trigger to set the value. This will override any inserted or updated value that the original operation set (as it will execute after the operation, as stated in it's definition).
CREATE TRIGGER utrProductSetDate ON Product
AFTER INSERT, UPDATE
AS
BEGIN
SET NOCOUNT ON
UPDATE P SET
Date = GETDATE()
FROM
inserted AS I
INNER JOIN Product AS P ON I.OtherColumns = P.OtherColumns -- Assuming PK or Unique columns join
END
Thanks all of you. But i solved my problem by putting my date Column of that table into datetime data type and i my query i have entered the date using getdate() method. It worked for me to save current date and time in my purchase and sale table.
I have a column named as recordTime in my Access DB table table1.
This column is of TEXT type right now, and most of its value are in format as: yyyy-mm-dd hh:nn:ss, but there are also some wrong records like this: yyyy-mm- ::.
Now I would like to change the data type of this column from TEXT to DATETIME. I tried with the following query but nothing happens:
ALTER TABLE table1
ALTER COLUMN recordTime DATETIME;
Am I doing it wrong?
Try running these:
ALTER TABLE table1 ADD NewDate DATE
Then run
UPDATE table1
SET NewDate = RecordTime
WHERE RIGHT(RecordTime,4) <> '- ::'
You can then delete the RecordTime and rename NewDate.
I prefer adding a new column just in case there are any issues with the UPDATE and you can compare the 'cleaned' column and the initial data before proceeding.
Is there a way to have a column in the table which auto-calculates the time difference between the start date and the end date as such?
(datediff(hour,[StartTime],[EndTime]))
ALTER TABLE yourTable
ADD yourColumn AS (datediff(hour,[StartTime],[EndTime]))
SQLFiddle DEMO
EDIT:
That was the syntax for alter table, off-course you can also define it during table creation
CREATE TABLE tbl1
(
startDate DATETIME,
enddate DATETIME,
diffCol AS (datediff(hour,startDate,enddate))
);
SSMS also have an option in table designer to add formula for computed columns
Assuming both StartTime and EndTime are columns on the same row of your table, you can use a computed column:
ALTER TABLE MyTable ADD TimeDiffHours AS DateDiff(hour,[StartTime],[EndTime]);