I want to add 1 day to date with time component.
My date is say for eg.
2020-09-10 18:30:00.000'
and I want to add 24 hours i.e expected output is
2020-09-11 18:30:00.000
I wrote SELECT DATEADD(day, DATEDIFF(day, 0, '2020-09-10 18:30:00.000'), 1) but this does not show the time component.
How to add date with time component?
SQL Server is really flexible about recognizing date formats, and will happily understand your string as a date if you put in within a date function. So, no need for explicit conversion from string to date, you can just do:
dateadd(day, 1, '2020-09-10 18:30:00.000')
Drop the datediff() in your attempt. And according to the documentation, the date is the third argument of the dateadd() function.
select dateadd(day, 1, convert(datetime, '2020-09-10 18:30:00.000') );
Output:
2020-09-11 18:30:00.000
Related
I run this query on redshift to add 1 momth to a specific timestamp that:
SELECT
DATEADD(month, 1, date '2021-08-12 18:37:19') AS date_interval;
The result is this:
2021-09-12 00:00:00.0
How do I need to modify the query so the result also comes with the correct time looking like this:
2021-09-12 18:37:19
If you want to do algebra on a timestamp, then you should start with a literal timestamp, not a date:
SELECT
DATEADD(month, 1, '2021-08-12 18:37:19') AS date_interval;
The problem with your current query is that the following is a date literal:
date '2021-08-12 18:37:19'
Hence, the time component of your timestamp will be "zeroed" out to midnight before you even add one month.
I have a task that I need to show the current date time as ending at 3:00:00 AM at current date. For example, GETDATE() returns the current date time when executes. I need to show it as 9/5/2019 3:00:00 AM instead. Below is my code:
DECLARE #END_SHIFT AS DATETIME
SET #END_SHIFT = '06:00:00 AM'
SELECT
NUMBER_ID,
GETDATE() AS CURRENT_DT,
GETDATE() - #END_SHIFT AS END_SHIFT_DATE
FROM table
My issue when running this is it does not return as ending at 3:00:00AM. Please let me know your direction.
Thanks,
H
A bit of an odd request for sure but you could simply use DATEADD.
SELECT dateadd(hour, 3, convert(datetime, convert(date, getdate())))
If you really need a "hard" time, one option is to use format()
Example
Select format(GetDate(),'yyyy-MM-dd 03:00')
Returns
2019-09-05 03:00
I am a complete noob to SQL and trying to understand why this query returns "115":
select datediff(yy, -3, getdate())
datediff takes three Parameter. The first is the interval, the second the start date and the third the end date. You are passing -3 as start date, there we can show:
SELECT CAST(-3 AS datetime) -- results in '1899-12-29 00:00:00.000'
And because 2014 - 1899 is 115, you will get this as result.
Because DATEDIFF() calculates an interval between 2 dates, and you specified year -3 in one of them.
Firstly, the date "zero" is 12/30/1899 on SQL server.
Secondly, your "-3" was an incorrect date format and it thus replaced it with its 0
2014 - 1899 = 115
Use DATEADD() instead to achieve what you want to do.
DateDiff gives difference in years/date/months etc based on what you have given in first parameter. second and third parameter are datetime values which will be used to calculate the difference i.e. (param2 datetime value - param3 datetime value).
Now in your case param2 is "-3"
run this queries in you ms sql and observe the outputs :
select CAST(-3 as datetime)
select GETDATE()
select datediff(yy, -3, getdate())
I've referred to this on MSDN but I'm still unsure what the second argument in the DATEDIFF function is doing in the following two examples:
SELECT DATEDIFF(yy,0,getdate()) --run on 14 Aug this returns 112
SELECT DATEDIFF(yy,1000,getdate()) --I chose 1000 arbitrarily and run on 14 Aug this returns 110
Usually I'll use DATEDIFF to find the number of days, or number of years between two months and the second argument is then a date.
Reason I'd like to understand the above is to ultimately understand the following:
SELECT DATEADD(yy, DATEDIFF(yy,0,GETDATE()), 0)
If you use an integer as the second argument (or for any datetime/smalldatetime assignment for that matter), this is interpreted as the number of days since 1900-01-01.
DECLARE #d1 DATETIME = 0, #d2 DATETIME = 1;
SELECT #d1, #d2;
Result:
1900-01-01 00:00:00.000 1900-01-02 00:00:00.000
Note that this doesn't work for new data types like DATE during direct assignment:
DECLARE #d DATE = 0;
Result:
Msg 206, Level 16, State 2, Line 1
Operand type clash: int is incompatible with date
But it can still work using date math, e.g.:
DECLARE #d DATE = DATEADD(YEAR, 0, SYSDATETIME());
SELECT #d;
Result:
2012-08-14
For these inconsistent reasons, I recommend you use proper date literals so that it is clear which date you mean and so that it works regardless of the data type. This is a habit I find hard to break, since typing 0 is so much easier than 19000101...
Consider below example to understand this concept better. 0 is default date "1900-01-01"
Below Query gives output as 2017-10-31 00:00:00.000
SELECT DATEADD(DAY, -1, DATEADD(MONTH, DATEDIFF(MONTH,0,SYSDATETIME())+3, 0))
Dividing the above query into various parts to understand the calculation.
-- 1414 Months since '1900-01-01'
SELECT DATEDIFF(MONTH,0,SYSDATETIME()) + 3
-- adding 1414 Months to Default date 1900 Produces '2017-11-01 00:00:00.000'
SELECT DATEADD(MONTH, DATEDIFF(MONTH,0,SYSDATETIME())+3, 0)
--Subtract 1 day from '2017-11-01 00:00:00:000' gives last day of previous month.
SELECT DATEADD(DAY, -1, DATEADD(MONTH, DATEDIFF(MONTH,0,SYSDATETIME())+3, 0))
The second argument to datediff() is a date.
The first example returns the "start" date of time in the SQL Server world. That would be 112 years before the current date.
The second example is rather non-sensical. As implemented, the dates are represented as number days since the earliest date. This is the number of years since 1000 days after the earliest date.
The last example adds a number of years to the base date. It then adds a number of months. Since the base date is 1/1/1900, this is giving you the first date of the day after the nth month in the yth year.
I want to get the previous month relative to the current date
SELECT datediff(mm,-1,2-2-2011)
This query gives 67 which is a wrong value .. where i went wrong ?
You can use DATEADD
eg.
SELECT DATEADD(month, -1, GETDATE())
This 2-2-2011 is not a valid date literal - you are subtracting 2 from 2 and then 2011 from the result - proper date literals are '2-2-2011' and #2-2-2011#. You can use GETDATE() to get the current date, instead of relying on a literal.
Nor should you be using DATEDIFF - it gives you the difference between dates.
You should be using DATEADD to calculate new dates.
Try this:
SELECT DATEADD(mm,-1, GETDATE())
This will get the date a month ago.
If you just want the month, you need to also use DATEPART:
SELECT DATEPART(mm, SELECT DATEADD(mm,-1, GETDATE()))
SELECT datepart(mm, dateadd(mm,-1,'2011/1/1') )
If you want the month before the current month, you want
SELECT MONTH(DATEADD(mm, -1, GETDATE()))
If you want the date for a month before the current date, you want
SELECT DATEADD(mm, -1, GETDATE())
BTW, SELECT datediff(mm,-1,2-2-2011) computes the number of months between day -1 and day -2011, which is 67 (2010 / 30). That's nowhere near what you seem to actually want.
You need to use DATEADD - not DATEDIFF
DATEDIFF calculates the difference between two dates - it doesn't add day or months to an existing date....
Also, you need to put your dates into single quotes: use '2-2-2011' instead of simply 2-2-2011.
And lastly: I would strongly recommend using the ISO-8601 date format YYYYMMDD (here: 20110202) - it will work regardless of the language and regional settings on your SQL Server - your date format will BREAK on many servers due to language settings.
DATEDIFF calculates the difference between your stating and ending dates
every date previous to the current date has a positive number and every date next to the current date has negative number, this works in geting your specific date weather it a day,month,year or hour to understand this better below is the syntax of datediff
DATEDIFF (your datetime type, your starting date,your ending date)
the function does (your ending date)-(your starting date)
in your case the below datediff will work just pefectly
SELECT DATEDIFF (month,[you_date_or_datetime_column],GETDATE()) = 1
You can use DATEADD try this code
For previous month
SELECT DATEADD(month, -1, GETDATE())
For 7 day previous
$date = date('Y-m-d',strtotime("-7 days"));
SELECT * FROM users WHERE `date` LIKE '%$date%'
$date varibale get previous date date