How do I get the days interval for prestodb? I can convert to milliseconds and convert these to number of days but I am looking if there is any shorter way to do this.
Example: I want to see how many days has it been since the first row inserted in a table.
SELECT
to_milliseconds(date(current_date) - min(created)) / (1000*60*60*24) as days_since_first_row
FROM
some_table
What I am hoping to see: (Either 1 of below)
SELECT
to_days(date(current_date) - min(created)) / (1000*60*60*24) as days_since_first_row
,cast(date(current_date) - min(created)) as days) as days_since_first_row2
FROM
some_table
Unfortunately, daylight savings breaks the solution from the accepted answer. DAY(DATE '2020-09-6' - DATE '2020-03-09') and DAY(DATE '2020-09-6' - DATE '2020-03-08') are both equal to 181 due to daylight savings time and DAY acting as a floor function on timestamps.
Instead, use DATE_DIFF:
DATE_DIFF('day', DATE '2020-09-6', DATE '2020-03-09')
Use subtraction to obtain an interval and then use day on the interval to get number of days elapsed.
presto:default> select day(current_date - date '2018-07-01');
_col0
-------
86
The documentation for this is at https://trino.io/docs/current/functions/datetime.html
Hello everyOne I need to get the AVERAGE of difference of two dates (timestamp)
I tried this
select AVG((sva.endTime - sva.startTime)) as seconds from SVATable sva;
but I got an error
93/5000
ORA-00932: Inconsistent data types; expected: NUMBER; got: INTERVAL DAY TO SECOND
You may use EXTRACT to get AVG seconds.
SELECT AVG (EXTRACT (SECOND FROM (sva.endTime - sva.startTime)))
AS avg_seconds
FROM SVATable sva;
This is an insidious problem in Oracle. Your calculation would work with the date data type, but it does not work with timestamps.
One solution is to extract the days, hours, minutes, and seconds from the interval. Another is to use date arithmetic. You can get fractions of a day by using:
select (date '2000-01-01' + (sva.endTime - sva.startTime)) - date '2000-01-01'
You can use the average and convert to seconds:
select avg( (date '2000-01-01' + (sva.endTime - sva.startTime)) - date '2000-01-01') * (60*60*24)
PreparedStatement psnmt=con.prepareStatement("SELECT (?)-(?) as DiffDate FROM dual");
psnmt.setTimestamp(1,ctenderdate);
psnmt.setTimestamp(2,btenderdate);
ResultSet resrt=psnmt.executeQuery();
if(!resrt.next())
{
out.println("No Records Found");
}
else
{
do
{
datediff=resrt.getString("DiffDate");
}
while(resrt.next());
System.out.println("the no of days Difference"+datediff);
}
ctenderdate=2015-06-27 00:00:00.0
btenderdate=2015-06-29 00:00:00.0
datediff=1 10:18:51.940000000
Expected datediff=2
How to round it off datediff to number of days
EDIT
Subtract TIMESTAMP values
If we really want to subtract two TIMESTAMP values, then we have to work with the INTERVAL DAY TO SECOND datatype that's returned. The easiest way to work with that is to use the EXTRACT function.
If want to return integer number of days (emulating the CEIL function) then we could test whether any part of the time (HOUR, MINUTE, SECOND) was non-zero. If they are all zero, we can use just the DAY portion. Otherwise, we have to add 1 to the DAY portion, and return that.
For example:
SELECT EXTRACT(DAY FROM diff.idts)
+ CASE
WHEN EXTRACT(HOUR FROM diff.idts) > 0
OR EXTRACT(MINUTE FROM diff.idts) > 0
OR EXTRACT(SECOND FROM diff.idts) > 0
THEN 1
ELSE 0
END
AS days_diff
FROM ( SELECT ? - ? AS idts FROM dual ) diff
ORIGINAL ANSWER
For Oracle database, you can perform this operation in the database:
SELECT CEIL(TO_DATE(?,'YYYY-MM-DD HH24:MI:SS.F')-TO_DATE(?,'YYYY-MM-DD HH24:MI:SS.F'))
FROM dual
This assumes the bind parameters are passed as strings, in format that matches the format model specified in the TO_DATE function, for example:
'2015-06-27 14:45:21.0'
(I'm assuming Oracle because of the use of the dual table, and because you are using subtraction operation between two dates. You would need a different statement for a different database.)
To unpack that expression a little bit...
The Oracle TO_DATE function converts a character string into an Oracle DATE value. The second argument is the format model, specifies that format of the first argument.
A subtraction operation between two DATE values returns the difference as a number of days (integer days plus fractional days.)
The CEIL function rounds a non-integer value up to the next higher integer.
FOLLOWUP
Q: how to use it with timestamp?
A: A subtraction of two TIMESTAMP values gets returned as an INTERVAL DAY TO SECOND datatype. And I'd prefer to avoid working with that.
In Oracle, when we do a subtraction of two DATE values, we get a decimal number. That's much easier to work with.
And in terms of "rounding" up a difference in days, I'm fine with disregarding fractional seconds.
If I had to pass in TIMESTAMP values, I would convert them to DATE values. The expressions above are already expecting string values, so I would just replace the ? with
TO_CHAR(?,'YYYY-MM-DD HH24:MI:SS')
If I had a requirement to pass in TIMESTAMP datatype, and return integer days difference rounded up, I would use a query like this:
SELECT CEIL( TO_DATE(TO_CHAR( ? ,'YYYY-MM-DD HH24:MI:SS'),'YYYY-MM-DD HH24:MI:SS')
- TO_DATE(TO_CHAR( ? ,'YYYY-MM-DD HH24:MI:SS'),'YYYY-MM-DD HH24:MI:SS')
) AS days_diff
FROM dual
Check out this link. There are answers for results in hours or minutes. What you are looking for should be similar.
My bad. I should not post just-a-link-answers. What you can do, as described there is:
SELECT TRUNC (SYSDATE) - TO_DATE ('10/20/2012', 'mm/dd/yyyy') FROM DUAL;
Notice the following details:
ENDDATE - STARTDATE will give you a number that corresponds to the
number of days between the two dates.
If you want the result in hours, multiply by 24; if minutes, multiply
by 24*60 and so forth.
You can also convert the result to an INTERVAL. There are two type of
intervals: NUMTODSINTERVAL(ENDDATE - STARTDATE, 'DAY') or
NUMTOYMINTERVAL(ENDDATE - STARTDATE, 'DAY')
I wish to convert a single Oracle datetime value to minutes.
As an example, I need to convert the current date/time alone into minutes, i.e.:
select (sysdate)*24*60 from dual
but this is giving me an error.
I basically need to perform a check to see that a certain operation cannot be performed until 30 minutes before a particular date/start time, that exists in the database.
So if the Start Time in the DB is:
24/04/2014 22:00:00 and the current date/time (SYSDATE) is 24/04/2014 21:29:59,
then operation CANNOT be performed but if the current date/time (SYSDATE) is:
24/04/2014 21:30:00,
then operation CAN be performed.
You probably want something like
startTime - interval '30' minute >= sysdate
or
startTime >= sysdate + interval '30' minute
You could also subtract the two date values which gives you the number of days between them and multiply
(startTime - sysdate)*24*60 >= 30
but I generally find the interval notation clearer and easier to read. It's also easier to structure in a way that allows you to use indexes on columns like startTime.
select (sysdate - trunc(sysdate)) *24 *60 from dual
You seem to want to know if the seconds component of sysdate is 0. So, test for that:
where extract(second from sysdate) = 0
Oops, I misread the question. You just need a difference of 30 minutes. That is also easy:
where starttime <= sysdate + 30/(24*60)
When you add an integer to a datetime, it is interpreted as a number of days. The expression 30/(24*60) is an expression for half an hour measured in days.
Is there a TIMESTAMPDIFF() equivalent for PostgreSQL?
I know I can subtract two timestamps to get a postgresql INTERVAL. I just want the difference between the two timestamps in in hours represented by an INT.
I can do this in MySQL like this:
TIMESTAMPDIFF(HOUR, links.created, NOW())
I just need the difference between two timestamps in hours represented as an integer.
Solution works for me:
SELECT "links_link"."created",
"links_link"."title",
(EXTRACT(EPOCH FROM current_timestamp - "links_link"."created")/3600)::Integer AS "age"
FROM "links_link"
The first things popping up
EXTRACT(EPOCH FROM current_timestamp-somedate)/3600
May not be pretty, but unblocks the road. Could be prettier if division of interval by interval was defined.
Edit: if you want it greater than zero either use abs or greatest(...,0). Whichever suits your intention.
Edit++: the reason why I didn't use age is that age with a single argument, to quote the documentation: Subtract from current_date (at midnight). Meaning you don't get an accurate "age" unless running at midnight. Right now it's almost 1am here:
select age(current_timestamp);
age
------------------
-00:52:40.826309
(1 row)
Get fields where a timestamp is greater than date in postgresql:
SELECT * from yourtable
WHERE your_timestamp_field > to_date('05 Dec 2000', 'DD Mon YYYY');
Subtract minutes from timestamp in postgresql:
SELECT * from yourtable
WHERE your_timestamp_field > current_timestamp - interval '5 minutes'
Subtract hours from timestamp in postgresql:
SELECT * from yourtable
WHERE your_timestamp_field > current_timestamp - interval '5 hours'
Michael Krelin's answer is close is not entirely safe, since it can be wrong in rare situations. The problem is that intervals in PostgreSQL do not have context with regards to things like daylight savings. Intervals store things internally as months, days, and seconds. Months aren't an issue in this case since subtracting two timestamps just use days and seconds but 'days' can be a problem.
If your subtraction involves daylight savings change-overs, a particular day might be considered 23 or 25 hours respectively. The interval will take that into account, which is useful for knowing the amount of days that passed in the symbolic sense but it would give an incorrect number of the actual hours that passed. Epoch on the interval will just multiply all days by 24 hours.
For example, if a full 'short' day passes and an additional hour of the next day, the interval will be recorded as one day and one hour. Which converted to epoch/3600 is 25 hours. But in reality 23 hours + 1 hour should be a total of 24 hours.
So the safer method is:
(EXTRACT(EPOCH FROM current_timestamp) - EXTRACT(EPOCH FROM somedate))/3600
As Michael mentioned in his follow-up comment, you'll also probably want to use floor() or round() to get the result as an integer value.
You can use the "extract" or "date_part" functions on intervals as well as timestamps, but I don't think that does what you want. For example, it gives 3 for an interval of '2 days, 3 hours'. However, you can convert an interval to a number of seconds by specifying 'epoch' as the time element you want: extract(epoch from '2 days, 3 hours'::interval) returns 183600 (which you then divide by 3600 to convert seconds to hours).
So, putting this all together, you get basically Michael's answer: extract(epoch from timestamp1 - timestamp2)/3600. Since you don't seem to care about which timestamp precedes which, you probably want to wrap that in abs:
SELECT abs(extract(epoch from timestamp1 - timestamp2)/3600)
postgresql get seconds difference between timestamps
SELECT (
(extract (epoch from (
'2012-01-01 18:25:00'::timestamp - '2012-01-01 18:25:02'::timestamp
)
)
)
)::integer
which prints:
-2
Because the timestamps are two seconds apart. Take the number and divide by 60 to get minutes, divide by 60 again to get hours.
extract(hour from age(now(),links.created)) gives you a floor-rounded count of the hour difference.
To avoid the epoch conversion you could extract the days multiply them by 24 and add the extraction of hours to it.
select current_timestamp, (current_timestamp - interval '500' hour), (extract(day from (current_timestamp - (current_timestamp - interval '500' hour)) * 24) + extract(hour from (current_timestamp - (current_timestamp - interval '500' hour))));
For MySQL timestampdiff I don't know, but for MSSQL datediff(hour, start, end) the best equivalent in PostgreSQL is floor(extract(epoch from end - start)/3600), because in MSSQL select datediff(hour,'2021-10-31 18:00:00.000', '2021-10-31 18:59:59.999') return 0
This might sound crazy to a lot of developers who like to take advantage of database functions,
But after exhaustive problems thinking, creating and bugfixing applications for mysql and postgrsql with php comparing date functions, I've come to the conclusion (for myself), that the easiest way, that is the simplest with less SQL headaches is not to take advantage of any of them.
Why? because if you are developing in a middleware language like PHP, PHP has all of these functions, and they are easier to implement in the application ode as comparing integers. PostgreSQL timestamp is NOT == UNIX TIMESTAMP and MySQL's UNIX TIMESTAMP is NOT PostgresQL's or Oracles timestamp.. it gets harder to port if you use database timestamps..
so just use an integer, not a timestamp,
as the number of seconds since january 1st 1970 midnight. and never mind database timestamps.
, and use gmdate() and store everything as gmt time to avoid timezone issues.
if you need to search, sort or compare the day from other data, or the month or the year or the day of the week, or anything, in your application,
and INTEGER datatype for time_day, time_hour, time_seconds.. or whatever you wnat to index to be searched will make for smoother and more portable databases.
you can just use one field, in most instances: INTEGER time_created NOT NULL
(more fields in your database row is the only drawback to this solution that i have found, and that doesnt cause as many headaches, or cups of coffee :)
php's date functions are outstanding to compare dates,
but in mysql or postgresql, comparing dates ? nah.. use integer sql comparisons
i realize it may SEEM easier to use CURRENT_TIMESTAMP on an insert function. HA!
don't be fooled.
You cant do DELETE FROM SESSION_TABLE WHERE time-initialized < '2 days'
if time-intitialized is a postgresql timestamp.
but you CAN do:
DELETE FROM SESSION_TABLE WHERE time_initialized < '$yesterday'
As long as you set $yesterday in php as the integer of seconds since 1970 that yesterday was.
This is easier housekeeping of session records than comparing timestamps in postgresql select statements.
SELECT age(), SELECT extract(), and asbtime are headaches in an of themselves. this is just my opinion.
you can do addition, substraction, <, >, all with php date objects
_peter_sysko
U4EA Networks, Inc.