I have a date time field in a MySQL database and wish to output the result to the nearest hour.
e.g. 2012-04-01 00:00:01 should read 2012-04-01 00:00:00
Update: I think https://stackoverflow.com/a/21330407/480943 is a better answer.
You can do it with some date arithmetic:
SELECT some_columns,
DATE_ADD(
DATE_FORMAT(the_date, "%Y-%m-%d %H:00:00"),
INTERVAL IF(MINUTE(the_date) < 30, 0, 1) HOUR
) AS the_rounded_date
FROM your_table
Explanations:
DATE_FORMAT: DATE_FORMAT(the_date, "%Y-%m-%d %H:00:00") returns the date truncated down to the nearest hour (sets the minute and second parts to zero).
MINUTE: MINUTE(the_date) gets the minute value of the date.
IF: This is a conditional; if the value in parameter 1 is true, then it returns parameter 2, otherwise it returns parameter 3. So IF(MINUTE(the_date) < 30, 0, 1) means "If the minute value is less than 30, return 0, otherwise return 1". This is what we're going to use to round -- it's the number of hours to add back on.
DATE_ADD: This adds the number of hours for the round into the result.
Half of the hour is a 30 minutes. Simply add 30 minutes to timestamp and truncate minutes and seconds.
SELECT DATE_FORMAT(DATE_ADD(timestamp_column, INTERVAL 30 MINUTE),'%Y-%m-%d %H:00:00') FROM table
soul's first solution truncates instead of rounding and the second solution doesn't work with Daylight Savings cases such as:
select FROM_UNIXTIME(UNIX_TIMESTAMP('2012-03-11 2:14:00') - MOD(UNIX_TIMESTAMP('2012-03-11 2:14:00'),300));
Here is an alternate method (1):
DATE_ADD(
tick,
INTERVAL (IF((MINUTE(tick)*60)+SECOND(tick) < 1800, 0, 3600) - (MINUTE(tick)*60)+SECOND(tick)) SECOND
)
If you don't need to worry about seconds you can simplify it like this (2):
DATE_ADD(
tick,
INTERVAL (IF(MINUTE(tick) < 30, 0, 60) - MINUTE(tick)) MINUTE
)
Or if you prefer to truncate instead of round, here is simpler version of soul's method (3):
DATE_SUB(tick, INTERVAL MINUTE(tick)*60+SECOND(tick) SECOND)
EDIT: I profiled some of these queries on my local machine and found that for 100,000 rows the average times were as follows:
soul's UNIXTIME method: 0.0423 ms (fast, but doesn't work with DST)
My method 3: 0.1255 ms
My method 2: 0.1289 ms
Ben Lee's DATE_FORMAT method: 0.1495 ms
My method 1: 0.1506 ms
From How to round a DateTime in MySQL?:
It's a little nasty when you do it with datetime data types; a nice candidate for a stored function.
DATE_SUB(DATE_SUB(time, INTERVAL MOD(MINUTE(time),5) MINUTE ),
INTERVAL SECOND(time) SECOND)
It's easier when you use UNIXTIME timestamps but that's limited to a 1970 - 2038 date range.
FROM_UNIXTIME(UNIX_TIMESTAMP(time) - MOD(UNIX_TIMESTAMP(time),300))
Good luck.
To round down to the current hour, select:
FROM_UNIXTIME(FLOOR(UNIX_TIMESTAMP(column_name) / 3600) * 3600).
The value is expressed in the current time zone doc
This will return the next hour, that is '2012-01-02 18:02:30' will be converted into '2012-01-02 19:00:00'
TIMESTAMPADD(HOUR,
TIMESTAMPDIFF(HOUR,CURDATE(),timestamp_column_name),
CURDATE())
Instead of CURDATE() you can use an arbitrary date, for example '2000-01-01'
Not sure if there could be problems using CURDATE() if the system date changes between the two calls to the function, don't know if Mysql would call both at the same time.
to get the nearest hour would be:
TIMESTAMPADD(MINUTE,
ROUND(TIMESTAMPDIFF(MINUTE,CURDATE(),timestamp_column_name)/60)*60,
CURDATE())
changing 60 by 15 would get the nearest 15 minutes interval, using SECOND you can get the nearest desired second interval, etc.
To get the previous hour use TRUNCATE() or FLOOR() instead of ROUND().
Hope this helps.
If you need to round just time to next hour you may use this:
SELECT TIME_FORMAT(
ADDTIME(
TIMEDIFF('16:15', '10:00'), '00:59:00'
),
'%H:00:00'
)
I think this is the best way, since it also will use the least amount of resources-
date_add(date(date_completed), interval hour(date_completed) hour) as date_hr
Related
SET #time := '2018-11-08 00:36:50.000000';
SET #intervalInMinutes := 15
SELECT FROM_UNIXTIME((Select FLOOR ((select UNIX_TIMESTAMP(#time) / (#intervalInMinutes* 60))) * (#intervalInMinutes*60)));
I need to write a query in MySQL that converts the date/time in the nearest interval category specified by the user.
Examples:
Eg 1: '2018-10-24 17:45:50.000000'
For an interval of 15 mins would translate to '2018-10-24 17:45:00'
For an interval of 30 mins would translate to '2018-10-24 17:30:00'
For an interval of 60 mins would translate to '2018-10-24 17:00:00'
Eg 2: '2018-10-24 17:36:20.000000';
For an interval of 15 mins would translate to '2018-10-24 17:30:00'
For an interval of 30 mins would translate to '2018-10-24 17:30:00'
For an interval of 60 mins would translate to '2018-10-24 17:00:00'
I have written the above query which seems to work fine. However, going by this post , the first answer has a comment that states that this approach will fail datetimes that fall between the daylight time savings. I dont get the example he specifies. The other approaches I notice on that thread looks even more complicated for my case. I am trying to understand how this would affect my scenario. Any suggestions/examples are appreciated.Or, is there a better way to avoid this by writing a simpler query ?
P.S. I want this to be applicable to MySQL 5.6,5.7 and 8.0.
The issue that you can face while using converting datetime to unixtime and back is quite OK explained in MySQL database.
So to be on a safe side I'd use another approach:
SET #time := '2018-11-08 00:36:50.000000';
SET #intervalInMinutes := 15;
SELECT TIMESTAMP(DATE(#time), SEC_TO_TIME(FLOOR(TIME_TO_SEC(TIME(#time)) / (#intervalInMinutes * 60)) * (#intervalInMinutes * 60)));
The idea is very similar: you are converting time to seconds, rounding and converting back.
I want to know is it possible in mysql query.. when I say give me date when it is 9am.. the return answer is depends upon current time when it is 8am it give me today's date. when it is 10pm it gives me tomorrow date. how it is possible in mysql query.
You can use SUBSTRING_INDEX(CURTIME(), ':', 1) to get the hours of current time.
As I understood you want to get tomorrow date, if it is 10pm or later
Example given:
SELECT
CASE
WHEN SUBSTRING_INDEX(CURTIME(), ':', 1) >= 22
THEN DATE_ADD(CURDATE(), INTERVAL 1 DAY)
ELSE CURDATE()
END
Source: http://www-db.deis.unibo.it/courses/TW/DOCS/w3schools/sql/sql_dates.asp.html
You can get the hour value from a given datetime expression, using HOUR function. CURDATE() function is used to return the current date. You can add/subtract 'integers' to it get the date corresponding to current date +/- 'integer days' . Assuming that the time >= 10 pm returns next day:
SELECT IF(HOUR(`datetime_field`) > 22, CURDATE(), CURDATE() + 1);
You could just add 2 hours
SELECT DATE(DATE_ADD(NOW(), INTERVAL 2 HOUR));
This will then return tomorrow’s date for anytime after 10pm.
I've got a column time type in mysql, i want to add 24 hours to this hour, i try with code below:
SELECT SUBSTRING(CAST(DATE_ADD(STR_TO_DATE('23:00', '%k:%i'), INTERVAL (TIME_TO_SEC('24:00') / 60) MINUTE) AS CHAR(8)), 1,5)
I need to return 23:00 again (because i add 24 hours but that 23:00 is of the next day) but this code return me 47:00.
Some help?
I think you're looking for ADDTIME
SELECT ADDTIME(‘23:00’,’24:00’)
https://dev.mysql.com/doc/refman/5.7/en/date-and-time-functions.html#function_addtime
You need to first convert the column value to a datetime, add the hours, and then convert the result back to time:
select cast(date_add(cast(time_column as datetime), interval 24 hour ) as time)
from yourtable;
Example:
select cast(date_add(cast(cast('23:00' as time) as datetime), interval 24 hour ) as time)
The TIME type allows you to store up to (but not including) 839 hours (positive and negative). That's great if you need to store duration, but not so much if you want to store time of day. If you want the latter you should consider the DATETIME type instead.
I am trying to do the following to calculate work velocity:
SELECT (count(*) / 1) velocity FROM mutable
WHERE timestamp > DATE(NOW()-INTERVAL 1 minute)
However, this seems to be returning a false result. What is the issue here, and how would I correctly do this query?
When you use date() you are converting the value to a date. That seems odd when you are subtracting one minute. If you want a count from the most recent minute, then try:
SELECT (count(*) / 1) as velocity
FROM mutable
WHERE timestamp > DATE_SUB(NOW(), INTERVAL 1 minute);
The problem is that you're wrapping the expression in DATE() which will return a timestamp that corresponds with the start of a day, i.e. yyyy-mm-dd 00:00:00. As such, your expression will change only daily.
You could use DATE_SUB() though:
timestamp > DATE_SUB(NOW(), INTERVAL 1 minute)
I am using this function to filter query results that are older than 60 days:
s.timeSubmitted >= ( CURDATE() - INTERVAL 60 DAY )
The problem is, the "60 days" part doesn't seem to be an exact figure. I want it to filter right where s.timeSubmitted is longer than 60 days, down to the exact second of s.timeSubmitted.
How do I write "60 Days" as an exact figure (down to the second)?
The problem is that CURDATE() returns a DATE type, not a DATETIME type (an instant in time). The result of subtracting an interval from a DATE is also a DATE.
Instead, try this:
s.timeSubmitted >= ( NOW() - INTERVAL 60 DAY )
This gives you what you want, because NOW() returns a DATETIME, so the result of the subtraction is also a DATETIME.
INTERVAL 60 DAY is exact - your problem is that CURDATE() isn't. It returns whole days, not the current time.
Use NOW() instead!
I usually do
now()-interval 60 day
Assuming you want the same time of day 60 days ago;
s.timeSubmitted >= ( now() - interval 60 day);
Maybe an un-necessary note in this case; 1 day ago may be 23, 24 or 25 hours ago depending on DST changes, if you want a specific number of hours as an interval, don't use a day instead of 24 hours.