I'm storing my dates in SQLite in a column of data type INTEGER. I'm storing the milliseconds since 1970.
Eg:
date (long) other columns ...
-----------------------------------------
1407297600000 ...
1407211200000 ...
1407124800000 ...
My question is: how can I use strftime() under this circumstances?
If not, I should use TEXT as the column type??
Running this:
select strftime('%Y-%m', date) from my_table;
Is throwing nonesense stuff:
strftime('%Y-%m', date)
-----------------------------------------
1968-19
1968-19
1968-19
Unless you tell it otherwise, strftime() thinks those numbers are Julian day values - very different from Unix epoch milliseconds.
You'll want to convert to seconds, and tell strftime() these are Unix epoch numbers:
select strftime('%Y-%m', date / 1000, 'unixepoch');
See the Modifiers section in the SQLite Date and Time Functions docs.
Related
I have a SQLite DB with the following columns:
File, Date_created, Owner
How do I get the list of files created in the last 30 days?
I tried the following, but it didn't limit the result. The list came back with files created 2 years ago!
SELECT * FROM Table1 WHERE Date_created > (SELECT DATETIME('now', '-30 day'))
Also, not sure if it matters, but my Created_date column is in the following date format: dd/mm/yyyy hh:mm:ss
SQLite doesn't have a native datetime data type, so that comparison's going to be on text. If your records are in DD/MM/YYYY format, you'll end up with comparisons like "07/03/2020" > "2020-06-07" which make little sense.
If you opt to store your datetimes as text, you must use a format that's lexicographically orderable. A great standard format that exhibits this property (if every piece of data has the same timezone, anyway) is ISO 8601, e.g. 2020-07-07 15:04:14+0300 at the time of writing in my timezone. As an aside, even xkcd recommends ISO 8601.
If you opt to store your datetimes as numbers, you can store them as either UNIX time, or maybe, if you're feeling adventurous, as e.g. the number 20200707150414. Do remember neither of these numeric options store timezone information, if that's important to your application.
As an aside,
SELECT * FROM Table1 WHERE Date_created > DATETIME('now', '-30 day')
is enough :)
Something like this might be what you are looking for, it's something that's come up in my head, haven't tested it.
Basically you're going 30 days backwards by Date_created.
SELECT * FROM Table1
WHERE DATEDIFF(DAY, DATEADD(DAY, -30, GETDATE()), Date_created) > 0
My demand is really so silly, so basically I need to go back in time 24 hours in a timestamp column in Hive.
So far, I have tried two different ways but it's not going thru:
select
recordDate, --original date
cast(date_sub(cast(recorddate as timestamp),1) as timestamp), -- going one day behind without hour
cast((cast(cast(recorddate as timestamp) AS bigint)-1*3600) as timestamp) -- crazy year
from mtmbuckets.servpro_agents_events limit 10;
My output looks:
I appreciate the support you can give me.
thanks
There is not straight forward function in hive .
1 Create UDF to do so .
or
Convert date in no of second and do you calculation( -24 *60*60) sec then change back int to data.
use from_unixtime and unix_timestamp to achieve below code.
select from_unixtime(unix_timestamp(recorddate) - 86400)
from mtmbuckets.servpro_agen ts_events limit 10;;
From_unixtime
Convert time string with given pattern to Unix time stamp (in seconds) The result of this function is in seconds.
Unix_timestamp
Converts time string in format yyyy-MM-dd HH:mm:ss to Unix timestamp (in seconds), using the default timezone and the default locale, return 0 if fail: unix_timestamp('2009-03-20 11:30:01') = 1237573801
When looking at the History.db from Safari, there's a table named history_visits which has a column named visit_time, which is a REAL value. It has values such as 470799793.096987. What format is that in? I'd like to see it in a format such as 12/08/2015 05:12:05.
It's the number in seconds since 00:00:00 UTC on 1 January 2001. It must be coming from an NSDate.
NSDate objects encapsulate a single point in time, independent of any particular calendrical system or time zone. Date objects are immutable, representing an invariant time interval relative to an absolute reference date (00:00:00 UTC on 1 January 2001).
— NSDate Class Reference
To get a decent human value out of it, you must add 978307200 (the epoch for 2001-01-01 00:00:00).
This query should give you what you want:
.headers on
select datetime(v.visit_time + 978307200, 'unixepoch', 'localtime') as date, v.visit_time + 978307200 as epoch, v.visit_time, i.domain_expansion, i.url
from history_items i left join history_visits v on i.id = v.history_item
order by i.id desc
limit 100;
Example output:
date|epoch|visit_time|domain_expansion|url
2015-12-31 11:51:27|1451562687.28465|473255487.284646|duckduckgo|https://duckduckgo.com/?q=current+timestamp+2015-12-31+11:51&t=osx
PS: Just for future reference, the Safari db file is located at ~/Library/Safari/History.db
To convert the visit_time value in the history.db in an excel spread sheet, open the history.db file in a tool such as DB browser for SQLLite (Windows) and export the history_visits values to a CSV file.
Open the CSV file and create a column where you will populate your values in human readable time adjusted to your time zone, and use the following formula convert your NSDate:
=((((C2+978307200)/60)/60)/24)+DATE(1970,1,1)+(-5/24)
In the above formula, the time value is in cell C2, and my time zone GMT-5. To adjust to your own time zone adjust the statement in the last set of parenthesis. Presently I have (-5/24) to represent GMT-5.
When I first approached this conversion, I mistakenly assumed the time in the history.db to be epoch time, which starts at 1/1/1970, and did not understand why there was such a skew in time. Adding the required conversion factor +978307200 solved the problem.
I found the domain_expansion field to be null in some cases, here's a modified query:
SELECT SUBSTR(
SUBSTR(url, INSTR(url, '/')+2),
1,
INSTR(SUBSTR(url, INSTR(url, '/')+2),'/') - 1
) domain,
url,
datetime(hv.visit_time + 978307200, 'unixepoch', 'localtime') visit_time
FROM history_items hi
JOIN history_visits hv on hi.id = hv.history_item;
Select distinct Format(DateAdd(""s""," & columnname & ",""1/1/1980 12:00:00 AM""), 'dd-MMM-yyyy') as A
I have assumed that the seconds to add and the original date are hard coded values below whilst awaiting clarifications requested in the comments.
To add a number of seconds to a date you can use:
select datetime('1980-01-01 00:00:00', "345000 seconds");
This gives the result: 1980-01-04 23:50:00
The example above is just under 4 days in seconds, if you want to truncate the result to just the date as implied by the query in your questions then you can wrap this inside a date function. However, this would give the result in the format "YYYY-MM-DD" rather than "DD-MMM-YYYY" as your access query does.
Unfortunately I cannot find any native SQLite function to convert a numeric month value to mmm format. You can do this manually with replace (similar to the answer to this question), but this is a bit messy.
If you are happy to live with the numeric months then you can simply use:
select strftime('%d-%m-%Y', '1980-01-01 00:00:00', "345000 seconds");
This gives the result: 04-01-1980
More information on the SQLite date / time functions can be found here.
I am trying to convert the following timestamp(in milliseconds since epoch) to normal date-time. Am using sqlite3 on windows xp.
I am using this query:
select datetime((timestamp/86400000)+25569) from table;
(timestamp is the column name which contains the values like 1289325613669,1289325823860,
1289327180545).
I dont seem to be getting the right values. Am i doing something wrong?
Do this:
select datetime('1289325613', 'unixepoch');
The unixepoch modifier expects a value in seconds.
Currently, what you provide to datetime is interpreted as a Julian Day number.
The reference for date and time functions is here