I have one table with always 1000 rows and a time column in the format hh:mm:ss. I need to count and get winner from minutes.
Something like:
|12:01:00|
|14:09:00|
|03:01:00|
|14:03:00|
|08:08:00|
So in this example minute 01 is the winner.
Appreciate any help.
Thanks
Get minute from the time using minute(date column) if it is MySQL or date_part(minute, date column) if it is in redshift DB or use mid() if it's a string.
Then do a group by with this extracted column and count it and find the winner.
Related
Hi I would like to find a query for the below, I am trying to calculate data between two columns however based on another column which needs to be a selected group of the same values
Unfiltered
Start Time________Disconnect Time______Signalling IP
12:59:00.3________13:26:03.3___________1.1.1.1
10:59:00.3________11:03:03.3___________2.2.2.2
19:59:00.3________20:02:03.3___________1.1.1.1
Filtered
Start Time________Disconnect Time______Signalling IP
12:59:00.3________13:26:03.3___________1.1.1.1
19:59:00.3________20:02:03.3___________1.1.1.1
If you see the table above, I want the selected IP only which is 1.1.1.1, and then from there, calculate the total duration of time from the Start Time and Disconnect Time for that Egress IP.
So column 3 has multiple values, however I need to select the same value, then from there calculate the sum of column 1 and 2 based on column 3.
Please let me know if you have anything in mind, as I have tried multiple queries but can't get the correct one
to calculate difference between to times.
you can use time_to_sec to convert each time value to seconds
and subtract start time from end time to get time period in seconds.
you cat turn it back to time format with SEC_TO_TIME
example
select
column3,
SEC_TO_TIME(sum(TIME_TO_SEC(column2) - TIME_TO_SEC(column1))
from
table
group by column3
If I have MySQL query like this, summing word frequencies per week:
SELECT
SUM(`city`),
SUM(`officers`),
SUM(`uk`),
SUM(`wednesday`),
DATE_FORMAT(`dateTime`, '%d/%m/%Y')
FROM myTable
WHERE dateTime BETWEEN '2011-09-28 18:00:00' AND '2011-10-29 18:59:00'
GROUP BY WEEK(dateTime)
The results given by MySQL take the first value of column dateTime, in this case 28/09/2011 which happens to be a Saturday.
Is it possible to adjust the query in MySQL to show the date upon which the week commences, even if there is no data available, so that for the above, 2011-09-28 would be replaced with 2011/09/26 instead? That is, the date of the start of the week, being a Monday. Or would it be better to adjust the dates programmatically after the query has run?
The dateTime column is in format 2011/10/02 12:05:00
It is possible to do it in SQL but it would be better to do it in your program code as it would be more efficient and easier. Also, while MySQL accepts your query, it doesn't quite make sense - you have DATE_FORMAT(dateTime, '%d/%m/%Y') in select's field list while you group by WEEK(dateTime). This means that the DB engine has to select random date from current group (week) for each row. Ie consider you have records for 27.09.2011, 28.09.2011 and 29.09.2011 - they all fall onto same week, so in the final resultset only one row is generated for those three records. Now which date out of those three should be picked for the DATE_FORMAT() call? Answer would be somewhat simpler if there is ORDER BY in the query but it still doesn't quite make sense to use fields/expressions in the field list which aren't in GROUP BY or which aren't aggregates. You should really return the week number in the select list (instead of DATE_FORMAT call) and then in your code calculate the start and end dates from it.
I have the following table in MySQL that records event counts of stuff happening each day
event_date event_count
2011-05-03 21
2011-05-04 12
2011-05-05 12
I want to be able to query this efficiently by date range AND by day of week. For example - "What is the event_count on Tuesdays in May?"
Currently the event_date field is a date type. Are there any functions in MySQL that let me query this column by day of week, or should I add another column to the table to store the day of week?
The table will hold hundreds of thousands of rows, so given a choice I'll choose the most efficient solution (as opposed to most simple).
Use DAYOFWEEK in your query, something like:
SELECT * FROM mytable WHERE MONTH(event_date) = 5 AND DAYOFWEEK(event_date) = 7;
This will find all info for Saturdays in May.
To get the fastest reads store a denormalized field that is the day of the week (and whatever else you need). That way you can index columns and avoid full table scans.
Just try the above first to see if it suits your needs and if it doesn't, add some extra columns and store the data on write. Just watch out for update anomalies (make sure you update the day_of_week column if you change event_date).
Note that the denormalized fields will increase the time taken to do writes, increase calculations on write, and take up more space. Make sure you really need the benefit and can measure that it helps you.
Check DAYOFWEEK() function
If you want textual representation of day of week - use DAYNAME() function.
Alright so here it is. I need to figure out the average amount of days between two columns.
Column 1 is recieved_date and column 2 is fix_date
Just want to know how to take the two dates find the difference in days, do that for every row and pop out a number stating the average amount of days it takes to fix something.
Tried to find it online but every time I find something like it, they have two specific dates. I need the entire columns averaged.
You can use the TIMESTAMPDIFF function both for dates and datetime.
See Mysql average time between visits
Add a group by and some other columns to this and it should do the trick:
select
avg(fix_period)
from
(
select
datediff(fix_date, received_date) as fix_period
from some_table
) as a
;
I have a table containing access logs. I want to know how many accesses to resource_id '123' occured in each hour in a 24 hour day.
My first thought for retrieving this info is just looping through each hour and querying the table in each loop with something like... and time like '$hour:%', given that the time field holds data in the format 15:47:55.
Is there a way I can group by the hours and retrieve each hour and the number of rows within each hour in a single query?
Database is MySQL, language is PHP.
SELECT HOUR(MyDatetimeColumn) AS h, COUNT(*)
FROM MyTable
GROUP BY h;
You can use the function HOUR to get the hour out of the time. Then you should be able to group by that.