I have a table from which I'm trying to extracted summed timediff information grouped by days. I don't really know if this is possible
Table columns: mode_type, start_time.
A record exists in this table for each time an employee starts or stops a timer. mode_type = 1 for start, mode_type = 0 for stop.
I'd like to return a sum of the seconds used for each day in the last 30 days.
E.g:
date, seconds_used
02/04/2014, 25
03/04/2014, 12415
04/04/2014, 925
Currently I can return a list of seconds used per mode_type and date but this required later calc in PHP.
SELECT
mode_type,
Sum(Unix_Timestamp(start_time)) AS time,
start_time
FROM
activations
WHERE
start_time < Date(Now() + INTERVAL 1 MONTH)
GROUP BY
mode_type, Day(start_time)
ORDER BY
start_time
I'm stuck... is this possible or do I need to do revert to calculating the diff in PHP post request?
Thanks in advance.
Can you try with this:
SELECT DATE(start_time) AS startdate, TIME_TO_SEC(TIMEDIFF(NOW(),start_time)) AS secs
FROM activations
GROUP BY
startdate
Related
Assuming that there are 6 months of historical data with hundreds of rides per day:
Write a query that returns, for each of the last 90 days, a count of the rides taken in the 7 day window preceding that day
I would like to find a way to write this in MySQL but have had some trouble with having a rolling sum that resets along with how I could cut up timestamps to reflect a day of the year/date and to then group by that.
I have tried writing subqueries that will limit the sum to a week prior and then place an additional limit of 90 days after that but cannot seem to get the code to return any output.
I have tried writing this is PostgreSQL using a sort of "window" functionality but am much more comfortable working in MySQL and would like to be able to solve it that way. I am familiar on how to write limits, group and order among other things but I am having trouble with the rolling sum resetting per week.
Thank you for your help!
First you'll want a numbers table/query. There are some tricky CTE ways to do that but it might be easier for now just to add a table with the numbers 1-90 in 90 rows.
Then use that to generate, for each row, a date range. Sorry if the syntax isn't quite correct, but write a query along the lines:
SELECT num, DATE_ADD(CURRENT_DATE(), INTERVAL -(num+7) DAY) startdate, DATE_ADD(CURRENT_DATE(), INTERVAL -num DAY) enddate FROM numbers
Then you can cross-join that with your rides table grouped on num and counting the rows in the range:
SELECT num, startdate, enddate, SUM(CASE WHEN startdate <= ridedate AND ridedate <=
enddate THEN 1 ELSE 0 END) ridecount
FROM (date range query) dts, rides
GROUP BY dts.num
Hope that helps.
Assuming you have data on each day, a correlated subquery might be simplest approach:
select dt,
(select count(*)
from rides r
where r.ridedate >= d.dte - interval 7 day and
r.ridedate < d.date
) as rolling_7
from (select distinct ridedate as dt
from rides
) dt
In MySQL, it is fairly easy to find the number of records that exist within some time interval.
SELECT COUNT(*) FROM records WHERE create_date > '2018-01-01 01:15:00' AND create_date < '2018-01-01 02:15:00'
But I want to do the opposite, sort of. Rather than providing a time interval and getting a count of records, I want to provide a count of records and check if a X minute time interval exists where more than Y many records were created. Getting the exact time interval is not essential, only if one exists or not. At a higher level, I am attempting to identify if there was any X minute "surge" when more than Y records where created during the course of a day.
For example, in the past 24 hours was there any 1 hour interval where a "surge" of more than 50 new records occurred?
I have already ruled out dividing the 24 hours into blocks of 1 hour intervals and checking each block. This does not work because the "surge" could span two sequential 1 hour blocks, such as 25 records at the end of the 01:00:00 block and 25 records at the beginning of the 02:00:00 block.
This should do it:
SELECT COUNT(*)
FROM records r1
WHERE
(SELECT COUNT(*) FROM records r2
WHERE ABS(UNIX_TIMESTAMP(r1.create_date) - UNIX_TIMESTAMP(r2.create_date)) < X) > Y
What this does is count how many records have more than Y records that have been created within X seconds after or before each record.
So basically it will return >=1 if there are any, 0 if not.
So if you wanted to sort by hours you would want to group the records. Here I'm using the built-in functions that return parts of a timestamp, year(), month(), dayofmonth(), hour(). Since you can't use an aggregate function in the where clause I had to use having to limit by the count requirement.
select date(create_date),
hour(create_date),
count(*) as surge from records
where create_date > curdate() - interval 1 day
group by year(create_date), month(create_date),
dayofmonth(create_date), hour(create_date)
having count(*) > 50;
Another method to accomplish your goal might be to select the count of records and group by the interval in question. In this case I'm adding an hour to the create_date to get your 1 hour suggested interval. Anytime the count is greater than 50 it returns a row. Notice I'm also grouping by the hour. This is to prevent multiple starts for a "surge" within the same hour:
select create_date,count(*) as surge from records
group by year(create_date), month(create_date),
dayofmonth(create_date),hour(create_date),
(create_date + interval 1 hour - create_date) having count(*) > 50;
The problem with this however is that some surges may last longer than 1 hour, but it should give you the moment the "surge" started.
Suppose I have a table containing a month's transaction data with transaction_time stored in a DATETIME field.
I want to get all the transactions that occurred between 12:00:00 and 13:00:00, irrespective of the day. WHERE transaction_time BETWEEN x AND y would have to be date-specific, but I need that same time period of all dates.
How can I filter for such a range in a MySQL query?
You can filter on the result of applying MySQL's HOUR() function to your DATETIME value:
WHERE HOUR(transaction_time) = 12
If you need to filter across more exact time ranges, you could convert the times to seconds as follows:
WHERE TIME_TO_SEC(TIME(transaction_time)) BETWEEN TIME_TO_SEC('12:00:00')
AND TIME_TO_SEC('13:00:00')
You can use:
select * from transactions
where convert(time, transaction_time) between '12:00:00' and '13:00:00'
for MSSQL and:
select * from transactions
where extract(hour_second from transaction_time) between 120000 and 130000
for MySql.
You have two time constraints. The first is to restrict the dates to a particular month. Assume we get the first day of the month as a date parameter:
where transaction_time >= :searchMonth
and transaction_time < Date_Add( :searchMonth, interval 1 month )
Now we're only looking at rows from that month. Now limit it to the hour specified. Assume we get the hour as an integer parameter:
and extract( hour from transaction_time ) between :hr and (:hr + 1)
Now that final part is based on your own code. Let me say that when the requirements read "during a particular hour of the day" and the request reads "during the noon hour" then I am wont to write it like this:
and extract( hour from transaction_time ) >= :hr
and extract( hour from transaction_time ) < (:hr + 1)
because hour 13 (1PM) is the first click of the next hour. So if there is a transaction time at exactly 13:00:00 and you use between, then it will show up when looking at the noon hour and also when looking at the 1PM hour. That is NOT generally a desired result. You may want to verify that with your analyst.
So the complete filter, the way I would write it, is this:
where transaction_time >= :searchMonth
and transaction_time < Date_Add( :searchMonth, interval 1 month )
and extract( hour from transaction_time ) >= :hr
and extract( hour from transaction_time ) < (:hr + 1)
For the below table, i would like to get the difference between last hour and current hour for col-D and col-E for each of the site.
As part of that I am trying to first get the latest (current) hour entries for each of the site, but the following query is only listing me the entries with endTime as 01:00:00, when i have entries upto 9.00AM
select distinct(mmeName), endDate, endTime, c_ratio, set_time from attach where
type='INIT' and Date(endDate)=curDate() and
Time(endTime) >= DATE_ADD(Time(endTime), INTERVAL -1 HOUR) group by mmeName;
Any help would be appreciated for the immediate issue and as well finding the difference between current and last hour.
EDITED
I think this is what you are looking for. This will give you any records where the endTime is one hour prior to the latest current time for each mmeName. The 'max' sub-select gets the latest end datetime for each mmeName, and the join back matches on record exactly one hour prior to that.
SELECT mmeName, endDate, endTime, c_ratio, set_time
FROM attach a
JOIN
(SELECT mmeName, CONCAT(endDate, ' ' , endTime) max_endDateTime
FROM attach
WHERE type = 'INIT'
ORDER BY endDate DESC, endTime DESC
) AS max ON max.mmeName = a.mmeName
AND max.max_endDateTime = DATE_ADD(CONCAT(endDate, ' ' , endTime), INTERVAL 1 HOUR)
WHERE type = 'INIT'
;
ORIGINAL
select mmeName, endDate, endTime, c_ratio, set_time
from attach
where type='INIT' and Date(endDate)=curDate() and
endTime >= DATE_SUB(now(), INTERVAL -1 HOUR)
group by mmeName;
Note: If there are multiple matching records for a given mmeName, this query will just grab one of them.
EDITED: You need drop the TIME() functions from the WHERE clause. Both would have the date and time and if you didn't, if you ran it between 12:00 AM to 1:00 AM it would not return any results.
Hi i am totally confused with a date logic in my mysql query for a cron job to be run everyday at 12:00 AM
I am working on a auto listing website where the car listings are having a expiry date in mysql datetime format.
All the expired listings will be deleted from the website after 7 days from the datetime of the expiry
When the cron job will run it has do following things
Task 1 - Send an email alert to the users telling them that their listing has expired.
So I need to select all those listings which have expired since last time the cron job has been run and not include listings before that in order to send the expiry alert email only once per listing.
I tried following sql query for this task (Again confused with this as well)
SELECT car_id FROM cars WHERE expiry_date > DATE_SUB(NOW(), INTERVAL 1 DAY) AND expiry_date < NOW()
Task 2 - Will send an email alert to users telling them that listing is going to be permanently deleted after 24 hours.
So I need to select all those listings which are going to be deleted in more than 24 hours / 6 days have passed since they were expired and i need to make sure that they get minimum 24 hours time to renew them. Also i need to select / build the sql query in such a way that only those listings get selected which are going to expiry in 1 days and not other in order to avoid multiple email alerts instead of one time email alert
I tried following sql query for this task (I am totally confused with this query)
SELECT car_id FROM cars WHERE expiry_date > DATE_SUB(NOW(), INTERVAL 7 DAY) AND expiry_date < DATE_SUB(NOW(), INTERVAL 1 DAY)
Task 3 - Delete all the listings which were expired more than 7 days ago
I tried following sql query for this task
SELECT car_id FROM cars WHERE expiry_date < DATE_SUB(NOW(), INTERVAL 7 DAY)
Please help me in perfecting all the 3 queries so that the cron does it job exactly as i want. Also please let me where it has to >= (greater than or equal to) or <= (less than or equal to)
Here is the sqlfiddle table structure and couple of records (though they are not expired yet)
http://sqlfiddle.com/#!2/cfcdf
I will really appreciate the help.
Is this what you are looking for? Please try to add another column to see the differnce between expiry_date and current date time for you to get a better idea of the dates you are dealing with. Please look into some dates functions in MYSQL.
SQLFIDDLE DEMO
-- 3rd query expiry dates older than 7 days from
-- today
SELECT car_id, expiry_Date,
DATE_sub(NOW(), INTERVAL 7 DAY)
FROM cars
WHERE expiry_date <=
DATE_sub(NOW(), INTERVAL 7 DAY)
;
-- same
SELECT car_id, expiry_Date,
DATE_ADD(NOW(), INTERVAL -7 DAY)
FROM cars
WHERE expiry_date <=
DATE_ADD(NOW(), INTERVAL -7 DAY)
;
-- 2nd query going to expire in exactly 1 day
SELECT car_id, expiry_date,
Now() + interval 1 day
FROM cars
WHERE expiry_Date = Now() + interval 1 day
;
-- 1st query: expired
SELECT car_id FROM cars
WHERE expiry_date < Now()
;
-- 1st query: expired last 24 hours
SELECT car_id,DATEDIFF(expiry_date, Now())
FROM cars
WHERE expiry_Date < Now()
AND expiry_Date >= Now() - interval 1 day
;
Check out these queries
select * from cars where datediff(EXPIRY_DATE,now())=-1;
select * from cars where
datediff(DATE_ADD(EXPIRY_DATE, interval 24 hour),now())>=1 and
datediff(DATE_ADD(EXPIRY_DATE, interval 24 hour),now()) <=2;
select * from cars where datediff(expiry_date,now())<=-7;
ope they are working according to your need.
fiddle http://sqlfiddle.com/#!2/785ea/5
There is nothing significantly wrong with your queries, if you do not understand the functions that you have used then google them and read about them until you do.
There is a fundamental problem in your approach in that it relies on the cron job being run at exactly 24 hour intevals - to the milisecond - or there will be double ups and/or omissions.
You need another table to store details of when your batch program last ran; intitialise this with 1 row with a date a long time in the past so that we have a starting point.
You can get the most recent batch by SELECT MAX(date_ran) FROM BatchRecordTables. Store this in a local variable T0. Get the current time, store this in a local variable T1 (Do not use NOW() in multiple queries as they will be slightly differant times and you need them to be the same). I do not know the syntax for this is MySQL - you will have to look it up.
Your situations then become.
Send email to people whose listings have expired since that last time the cron job was run i.e. SELECT car_id FROM cars WHERE Expiry_Date BETWEEN T0 AND T1. This will only select people whoose listings have expired between this batch and the previous one.
For the second case, we need to know that these people have got the first email i.e. that their listing had expired before the last batch run so SELECT car_id FROM cars WHERE Expiry_Date BETWEEN DATE_SUB(T1, INTERVAL 6 DAY) AND T0. This will only select people whoose listings expired before the last batch (i.e. they got the exprired email) and more than 6 days ago.
Same logi applies - we want to know they got the second email. SELECT car_id FROM cars WHERE Expiry_Date BETWEEN DATE_SUB(T1, INTERVAL 7 DAY) AND DATE_SUB(T0, INTERVAL 6 DAY)
May I also suggest that you do not permenantly delete the listings but either copy them to a DeletedListings table or Flag them with a Deleted column - each has its own pros and cons. In the information age, never throw data away - you never know when it might be valuable.