I have bigint value 635107999009730000.
I'm using this statement to convert this bigint to datetime:
select dateadd(second, 635107999009730000 /1000 + 635107999009730000 % 1000 + 8*60*60, '19700101')
I'm getting overflow error. Looks like dateadd function just cannot handle this bigint value.
How can I convert 635107999009730000 to datetime?
635107999009730000 value is grabbed from Microsoft LYNC 2013 database and I don't really know what datetime this should be.
I may be off the mark here but that value looks like nanoseconds and if that is the case you just have to divide it by a billion to get the seconds and add it to the unix time:
select dateadd(second, 635107999009730000 / 1000000000, '19700101')
You will have to test this against you data.
I ran into the same issue today. Both user1016945 and Suroh are correct to a degree. It is 10^7 ticks per second staring with 0001-01-01. So I slightly modified Suroh's statement. Since i'm not SQL expert, it's clumsy, but it work. You will lose seconds though. It overflows if I try to include seconds:
dateadd(year, -2000, dateadd(minute, 635107999009730000 / 600000000, '2001-01-01'))
I subtract 2000 years because I don't know how to pass 0001-01-01 to SQL. :)
Related
I'm looking to cast/convert a decimal data into date data. I've looked online and am still struggling. Can you help? "value" is a double precision, and here I convert it to varchar. From that point on, I've tried using convert but I'm still unable to get a date value.
Thanks in advance!
select cast(value as varchar(8) )date_value, value,
For example: The value 43099 should read 12/30/2017.
Guessing from your meager example, you might want this:
SELECT date '1899-12-30' + 43099; -- returns date '2017-12-30'
You need to cast your value column to integer for this:
SELECT date '1899-12-30' + value::int;
Meaning, the number might represent the count of days since 1900 (with an off-by-2 error I can't explain).
Adding an integer to a date means adding the number of days.
If your value can have fractional digits, you can compute a timestamp in similar fashion:
SELECT timestamp '1899-12-30' + interval '1 day' * value;
Can anyone suggest me, the easiest way to find summation of time field in POSTGRESQL. i just find a solution for MYSQL but i need the POSTGRESQL version.
MYSQL: https://stackoverflow.com/questions/3054943/calculate-sum-time-with-mysql
SELECT SEC_TO_TIME(SUM(TIME_TO_SEC(timespent))) FROM myTable;
Demo Data
id time
1 1:23:23
2 4:00:23
3 9:23:23
Desired Output
14:47:09
What you want, is not possible. But you probably misunderstood the time type: it represents a precise time-point in a day. It doesn't make much sense, to add two (or more) times. f.ex. '14:00' + '14:00' = '28:00' (but there are no 28th hour in a day).
What you probably want, is interval (which represents time intervals; hours, minutes, or even years). sum() supports interval arguments.
If you use intervals, it's just that simple:
SELECT sum(interval_col) FROM my_table;
Although, if you stick to the time type (but you have no reason to do that), you can cast it to interval to calculate with it:
SELECT sum(time_col::interval) FROM my_table;
But again, the result will be interval, because time values cannot exceed the 24th hour in a day.
Note: PostgreSQL will even do the cast for you, so sum(time_col) should work too, but the result is interval in this case too.
I tried this solution on sql fieddle:
link
Table creation:
CREATE TABLE time_table (
id integer, time time
);
Insert data:
INSERT INTO time_table (id,time) VALUES
(1,'1:23:23'),
(2,'4:00:23'),
(3,'9:23:23')
query the data:
SELECT
sum(s.time)
FROM
time_table s;
If you need to calculate sum of some field, according another field, you can do this:
select
keyfield,
sum(time_col::interval) totaltime
FROM myTable
GROUP by keyfield
Output example:
keyfield; totaltime
"Gabriel"; "10:00:00"
"John"; "36:00:00"
"Joseph"; "180:00:00"
Data type of totaltime is interval.
I'm trying to get difference in days, casting result to decimal:
SELECT
CAST( TO_DATE('2999-01-01','yyyy-mm-dd') - TO_DATE('2909-01-01','yyyy-mm-dd') AS DECIMAL )
;
Now if I add 1 month to the 2nd date:
SELECT
CAST( TO_DATE('2999-01-01','yyyy-mm-dd') - (TO_DATE('2909-01-01','yyyy-mm-dd') + INTERVAL '1 MONTH' * (1) ) AS DECIMAL )
;
I'm getting an error:
ERROR: cannot cast type interval to numeric
OK, I can cast to char to get result:
SELECT
CAST( TO_CHAR( TO_DATE('2909-02-10','yyyy-mm-dd') - (TO_DATE('2909-01-01','yyyy-mm-dd') + INTERVAL '1 MONTH' * (1) ), 'DD') AS DECIMAL )
;
But in this case the 1st query modified with TO_CHAR casting stop working:
SELECT
CAST( TO_CHAR(TO_DATE('2999-01-01','yyyy-mm-dd') - TO_DATE('2909-01-01','yyyy-mm-dd'), 'DD') AS DECIMAL )
;
I'm getting ERROR: multiple decimal points.
So, my question is, how can I get days using the same sql statement? For both sql queries.
Look at your first two examples again. If you remove the outer CAST ... AS DECIMAL you get
?column?
----------
32872
?column?
------------
32841 days
Clearly the difference is in the "days". The second is an interval value rather than a simple number. You only want the number (because you always just want days) so you need to extract that part. Then you can cast to whatever precision you like:
SELECT extract(days FROM '32841 days'::interval)::numeric(9,2);
date_part
-----------
32841.00
Edit responding to Alexandr's follow-up:
Your first example fails with a fairly specific error:
SELECT extract(days FROM (TO_DATE('2999-01-01','yyyy-mm-dd') - TO_DATE('2909-01-01','yyyy-mm-dd'))::interval)::numeric(9,2);
ERROR: cannot cast type integer to interval
LINE 1: ...yyyy-mm-dd') - TO_DATE('2909-01-01','yyyy-mm-dd'))::interval...
Here you've got an integer (which is what you originally wanted) and try to cast it to an interval (for reasons I don't understand). It's complaining it doesn't know what units you want. You want 32872 what in your interval - seconds, hours, weeks, centuries?
The second example is complaining because you are trying to extract the "day" part from a simple integer, and of course there's no extract() function in the system to do that.
I think you probably need to take a step back and just take the time to understand the values your various expressions return.
Subtracting one date from another gives the number of days separating them - as an integer. There is no other sensible measure, really.
Adding (or subtracting) an interval to a date gives you a timestamp (without time zone) since the interval may contain whole days, days and hours, seconds etc.
Subtracting a timestamp from a date will give you an interval since the result may contain days, hours, seconds etc.
If you have an interval and you just want the days part then you use extract() on it and you will get an integer number of days back.
You will need an integer (or floating-point) number of days if you want to cast to numeric, not an interval because casting an interval to an scalar number makes no sense without units.
So - either stick to dates and date arithmetic (easy), or realise you are using timestamps (flexible) but understand which it is.
To get an illustration of what's happening you can do something like this (in psql):
CREATE TEMP TABLE tt AS SELECT
('2909-01-02'::date - '2909-01-01'::date) AS a,
('2909-01-02'::date - '2909-01-02 00:00:00'::timestamp) AS b;
\x
SELECT * FROM tt;
\d tt
That will show you the values and types you are dealing with. Repeat for as many columns as you find useful.
HTH
If you're doing interval arithmetic with dates, you should generally be using timestamps instead, as mentioned in the docs.
# SELECT extract(days FROM TO_TIMESTAMP('2999-01-01','yyyy-mm-dd') - TO_TIMESTAMP('2909-01-01','yyyy-mm-dd'))
date_part
-----------
32872
# SELECT extract(days FROM TO_TIMESTAMP('2999-01-01','yyyy-mm-dd') - (TO_TIMESTAMP('2909-01-01','yyyy-mm-dd') + '1 month'::interval) );
date_part
-----------
32841
The result of adding an interval to a date is actually a timestamp, not another date (the interval might have contained time portions), so you have to cast the result of the addition back down to date first:
SELECT
CAST( TO_DATE('2999-01-01','yyyy-mm-dd')
- CAST( (TO_DATE('2909-01-01','yyyy-mm-dd') + INTERVAL '1 MONTH' * (1) ) AS DATE)
AS DECIMAL )
In Scaling Up Your Data Warehouse with SQL Server 2008 R2, the author recommends using an integer date key in the format of YYYYMMDD as a clustered index on your fact tables to help optimize query speed.
What is the best way to convert your key date field to the Date Key? I feel the following would work, but is a bit sloppy:
select Replace(CONVERT(varchar,GETDATE(),102),'.','')
Clearly, I'm not using getdate, but rather a date column in the table that will be using in my aggregations.
First, how would you suggest making this conversion? Is my idea acceptable?
Second, has anyone had much success using the Date Key as a clustered index?
ISO long (112) would do the trick:
SELECT CONVERT(INT, CONVERT(VARCHAR(8), GETDATE(), 112))
Casting getdate() straight to int with ISO 112 gives 41008 for some reason, but going via a VARCHAR seems to work - i'll update if i think of a faster cast.
EDIT: In regards to the int only vs varchar debate, here are my findings (repeatable on my test rig & production server) Varchar method uses less cpu time for half a million casts but a fraction slower overall - negligible unless your dealing with billions of rows
EDIT 2: Revised test case to clear cache and differnt dates
DBCC FREEPROCCACHE;
DBCC DROPCLEANBUFFERS;
SET STATISTICS TIME ON;
WITH RawDates ( [Date] )
AS ( SELECT TOP 500000
DATEADD(DAY, N, GETDATE())
FROM TALLY
)
SELECT YEAR([Date]) * 10000 + MONTH([Date]) * 100 + DAY([Date])
FROM RawDates
SET STATISTICS TIME OFF
(500000 row(s) affected)
SQL Server Execution Times:
CPU time = 218 ms, elapsed time = 255ms.
DBCC FREEPROCCACHE;
DBCC DROPCLEANBUFFERS;
SET STATISTICS TIME ON;
WITH RawDates ( [Date] )
AS ( SELECT TOP 500000
DATEADD(DAY, N, GETDATE())
FROM TALLY
)
SELECT CONVERT(INT, CONVERT(VARCHAR(8), [Date], 112))
FROM RawDates
SET STATISTICS TIME OFF
(500000 row(s) affected)
SQL Server Execution Times:
CPU time = 266 ms, elapsed time = 602ms
Converting to strings and back again can be surprisingly slow. Instead, you could deal entirely with integers, like this:
Select Year(GetDate()) * 10000 + Month(GetDate()) * 100 + Day(GetDate())
In my brief testing, this is slightly faster than converting to string and then to int. The Year, Month and Day function each returns an integer, so the performance is slightly better.
Instead of creating a DateKey using the YYYYMMDD format, you could use the DATEDIFF function to get the number of days between 0 (i.e. "the date represented by 0") and the date you're making the DateKey for.
SELECT DATEDIFF(day,0,GETDATE())
The drawback is that you can't easily look at the value and determine the date, but you can use the DATEADD function to calculate the original date (I've also seen this trick used truncate the time part of a datetime).
SELECT DATEADD(day, 41007, 0)
(Note: 41007 is the result of the DATEDIFF function above when I ran it on 4/10/2012.)
I have time, select cast(SYSDATETIME() AS time)
14:59:09.2834595
What is the way to truncate seconds?
14:59
Description
You can use the T-SQL function convert.
Sample
PRINT convert(varchar(5), SYSDATETIME(), 108)
will give you hh:mm
More Information
MSDN - CAST and CONVERT
If you want to truncate seconds and still have a T-SQL Date datatype, first convert the date into minutes from the date '0' and then add the minutes back to '0'. This answer doesn't require any additional parsing/converting. This method works to truncate other parts just change MINUTE.
Example:
SELECT DATEADD(MINUTE, DATEDIFF(MINUTE, 0, '2016-01-01 23:22:56.997'), 0)
If you need to drop seconds off entirely, you can use the DATEPART() function (SQL Server) to strip out the hour and minute, then append it back together. (I like dknaack's solution more, if that works.)
SELECT CAST(DATEPART(hour, SYSDATETIME()) + ':' + DATEPART(minute, SYSDATETIME()) AS DATETIME)
select cast(left(cast(SYSDATETIME() AS time), 5) as time)