Comparing results with today's date?

Question

Is there a way to use the Now() function in SQL to select values with today\'s date?

I was under the impression Now() would contain the ti

Answer 1

Building on the previous answers, please note an important point, you also need to manipulate your table column to ensure it does not contain the time fragment of the datetime datatype.

Below is a small sample script demonstrating the above:

select getdate()
--2012-05-01 12:06:51.413
select cast(getdate() as date)
--2012-05-01

--we're using sysobjects for the example
create table test (id int)
select * from sysobjects where cast(crdate as date) = cast(getdate() as date)
--resultset contains only objects created today
drop table test

I hope this helps.

EDIT:
Following @dwurf comment (thanks) about the effect the above example may have on performance, I would like to suggest the following instead. We create a date range between today at midnight (start of day) and the last millisecond of the day (SQL server count up to .997, that's why I'm reducing 3 milliseconds). In this manner we avoid manipulating the left side and avoid the performance impact.

select getdate()
--2012-05-01 12:06:51.413
select dateadd(millisecond, -3, cast(cast(getdate()+1 as date) as datetime))
--2012-05-01 23:59:59.997
select cast(getdate() as date)
--2012-05-01

create table test (id int)
select * from sysobjects where crdate between cast(getdate() as date) and dateadd(millisecond, -3, cast(cast(getdate()+1 as date) as datetime))
--resultset contains only objects created today
drop table test

Answer 2

OK, lets do this properly. Select dates matching today, using indexes if available, with all the different date/time types present.

The principle here is the same in each case. We grab rows where the date column is on or after the most recent midnight (today's date with time 00:00:00), and before the next midnight (tomorrow's date with time 00:00:00, but excluding anything with that exact value).

For pure date types, we can do a simple comparison with today's date.

To keep things nice and fast, we're explicitly avoiding doing any manipulation on the dates stored in the DB (the LHS of the where clause in all the examples below). This would potentially trigger a full table scan as the date would have to be computed for every comparison. (This behaviour appears to vary by DBMS, YMMV).

MS SQL Server: (SQL Fiddle | db<>fiddle)

First, using DATE

select * from dates 
where dte = CAST(CURRENT_TIMESTAMP AS DATE)
;

Now with DATETIME:

select * from datetimes 
where dtm >= CAST(CURRENT_TIMESTAMP AS DATE)
and dtm < DATEADD(DD, 1, CAST(CURRENT_TIMESTAMP AS DATE))
;

Lastly with DATETIME2:

select * from datetimes2
where dtm2 >= CAST(CURRENT_TIMESTAMP AS DATE)
and dtm2 < DATEADD(DD, 1, CAST(CURRENT_TIMESTAMP AS DATE))
;

---

MySQL: (SQL Fiddle | db<>fiddle)

Using DATE:

select * from dates 
where dte = cast(now() as date)
;

Using DATETIME:

select * from datetimes 
where dtm >= cast((now()) as date)
and dtm < cast((now() + interval 1 day) as date)
;

---

PostgreSQL: (SQL Fiddle | db<>fiddle)

Using DATE:

select * from dates 
where dte = current_date
;

Using TIMESTAMP WITHOUT TIME ZONE:

select * from timestamps
where ts >= 'today'
and ts < 'tomorrow'
;

---

Oracle: (SQL Fiddle)

Using DATE:

select to_char(dte, 'YYYY-MM-DD HH24:MI:SS') dte
from dates 
where dte >= trunc(current_date)
and dte < trunc(current_date) + 1
;

Using TIMESTAMP:

select to_char(ts, 'YYYY-MM-DD HH24:MI:SS') ts
from timestamps
where ts >= trunc(current_date)
and ts < trunc(current_date) + 1
;

---

SQLite: (SQL Fiddle)

Using date strings:

select * from dates 
where dte = (select date('now'))
;

Using date and time strings:

select dtm from datetimes
where dtm >= datetime(date('now'))
and dtm < datetime(date('now', '+1 day'))
;

Using unix timestamps:

select datetime(dtm, 'unixepoch', 'localtime') from datetimes
where dtm >= strftime('%s', date('now'))
and dtm < strftime('%s', date('now', '+1 day'))
;

---

Backup of SQL Fiddle code

Answer 3

There is no native Now() function in SQL Server so you should use:

select GETDATE() --2012-05-01 10:14:13.403

you can get day, month and year separately by doing:

select DAY(getdate())  --1
select month(getdate())  --5
select year(getdate()) --2012

if you are on sql server 2008, there is the DATE date time which has only the date part, not the time:

select cast (GETDATE() as DATE) --2012-05-01

Answer 4

Not sure exactly what you're trying to do, but it sounds like GETDATE() is what you're after. GETDATE() returns a datetime, but if you're not interested in the time component then you can cast to a date.

SELECT  GETDATE()
SELECT  CAST(GETDATE() AS DATE)