Let's say that my first column is time. What I want is to be able to count the rows grouping them by an arbitrary time range, for instance: by day, by hour, by 20 minutes intervals, by 15 seconds etc.
Convert the timestamp into some appropriate number (here: number of seconds since the Unix epoch), then do an integer division by the number of seconds (which implicitly rounds down):
SELECT ...
GROUP BY strftime('%s', MyDate) / 15 -- or 20*60 etc.
Related
I have a column 'Duration' it holds the time the therapist spent with the client.
This is always entered as minutes so if the time was 3 hours it is entered as 180. I would like to set this in the query as 3.
This is how it is reporting from a canned report: Total duration time is the entered column, it is
defined as int,null. I would like to make this calculation and formatiing, in the sql for the shown column 'total duration'.
total_duration_num total_duration
10 0:10
120 2:00
30 0:30
5 0:05
60 1:00
One means of achieving this is to use:
the floor function to round down when dividing the minutes by 60 (for whole hours)
the mod function to get the remaining number of minutes after putting however many can fit into "whole" 60-minute hours
the lpad function to put a leading zero before that number of minutes, if <10, so that you see :05 rather than :5 for example
The query would look like this:
select duration,
concat( floor(duration/60) , ':' , lpad(mod(duration,60),2,'0') ) as hrs_mins
from duration_table;
This is a demonstration:
http://sqlfiddle.com/#!9/a52b6c/1/0
I have a table with a start time and an end time (datetime, example: 2021-07-09 17:12:00) in each row.
When I calculate the sum of all differences between end time and start time by this SQL query:
SELECT
TIME(SUM(TIMEDIFF(`end_time`, `start_time`))) AS TimeDiff
FROM
my_table
I get a result expressed in hours, minutes, seconds (example: 00:02:00)
Now I need to calculate the average time expressed in hours, minutes, seconds of this sum.
It means:
SELECT
TIME(SUM(TIMEDIFF(`end_time`, `start_time`))) AS TimeDiff
FROM
my_table
TimeDiff/number of rows (expressed in hours, minutes, seconds)
Can you help me? Really thanks
Going out on a limb and guessing you're using MySQL due to the TIMEDIFF function.. Always state what DB you use; SQL is a standard, not a product
You asked about converting times to seconds and back, it probably looks like:
SELECT SEC_TO_TIME(AVG(TIME_TO_SEC(TIMEDIFF(end_time, start_time)))) FROM ...
I am creating a table which will have 2 columns:
Day_time (time from 1978-01-01 00:00:00 Sunday, till 1978-01-07 23:59:00.0 Saturday, Granularity: Minute)
Time_id (a unique id for each minute), to be populated
I have column one populated. I want to populate column two.
How I am doing it right now:
EXTRACT(dayofweek FROM day_time) * 10000 + DATEDIFF('minutes', TRUNC(day_time), day_time)
I basically want a function where I pass any date and it tells me where I am in a week. So, I need a function, just like the function above. Just more optimized, where I give a date and get a unique ID. The unique ID should repeat weekly.
Example: ID for Jan 1, 2015 00:00:00 will be same as Jan 8, 2015 00:00:00.
Why 1978-01-01? cuz it starts from a Sunday.
Why 10,000? cuz the number of minutes in a day are in four digits.
You can do it all in one fell swoop, without needing to extract the date separately:
SELECT DATEDIFF('minutes', date_trunc('week',day_time), day_time) which I'd expect to be marginally faster.
Another approach that I'd expect to be significantly faster would be converting the timestamp to epoch, dividing by 60 to get minutes from epoch and then taking the value modulus of 10,080 (for 60 * 24 * 7 minutes in a week).
SELECT (extract(epoch from day_time) / 60) % 10080
If you don't care about the size of the weekly index, you could also do:
SELECT (extract(epoch from day_time)) % 604800 and skip the division step altogether, which should make it faster still.
I have a table that lists activity for people and start / end timed for activity.
How do I get total amount of records for each person?
SELECT NAME,
--sum(startDT- endDT) AS minutes -- stuck here
FROM TABLE1
GROUP BY NAME
You're subtracting end time from start time, which will produce a negative value - try flipping those around (subtract start time from end time). The following will give you the number of records and the total elapsed time for each NAME:
SELECT NAME,
COUNT(*) AS "Records for NAME",
TO_CHAR(NUMTODSINTERVAL(SUM(END_DATE_TIME - START_DATE_TIME), 'DAY')) AS MINUTES
FROM TABLE1
GROUP BY NAME
SQLFiddle here
Share and enjoy.
Assuming that startDT and endDT are both of type date, you were really close. Subtracting two dates gives a difference in days. Multiply by 24 to get a difference in hours and again by 60 to get minutes
SELECT NAME,
sum(endDT - startDT)*24*60 AS minutes -- stuck here
FROM TABLE1
GROUP BY NAME
Assuming that your differences aren't always an exactly even number of minutes, you'll either get a non-integer result (e.g. 12.5 for 12 minutes 30 seconds) here or you'll want to either round or trunc the sum to get an integer number of minutes.
This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
What is the fastest way to truncate timestamps to 5 minutes in Postgres?
Postgresql SQL GROUP BY time interval with arbitrary accuracy (down to milli seconds)
I want to aggregate data at 5 minute intervals in PostgreSQL. If I use the date_trunc() function, I can aggregate data at an hourly, monthly, daily, weekly, etc. interval but not a specific interval like 5 minute or 5 days.
select date_trunc('hour', date1), count(*) from table1 group by 1;
How can we achieve this in PostgreSQL?
SELECT date_trunc('hour', date1) AS hour_stump
, (extract(minute FROM date1)::int / 5) AS min5_slot
, count(*)
FROM table1
GROUP BY 1, 2
ORDER BY 1, 2;
You could GROUP BY two columns: a timestamp truncated to the hour and a 5-minute-slot.
The example produces slots 0 - 11. Add 1 if you prefer 1 - 12.
I cast the result of extract() to integer, so the division / 5 truncates fractional digits. The result:
minute 0 - 4 -> slot 0
minute 5 - 9 -> slot 1
etc.
This query only returns values for those 5-minute slots where values are found. If you want a value for every slot or if you want a running sum over 5-minute slots, consider this related answer:
PostgreSQL: running count of rows for a query 'by minute'
Here's a simple query you can either wrap in a function or cut and paste all over the place:
select now()::timestamp(0), (extract(epoch from now()::timestamptz(0)-date_trunc('d',now()))::int)/60;
It'll give you the current time, and a number from 0 to the n-1 where n=60 here. To make it every 5 minutes, make that number 300 and so on. It groups by the seconds since the start of the day. To make it group by seconds since year begin, hour begin, or whatever else, change the 'd' in the date_trunc.