how to count days between two dates with where conditions - sql

Question

i have table and it has following data:
USERID NAME DATEFROM DATETO
1 xxx 2014-05-10 2014-05-15
1 xxx 2014-05-20 2014-05-25
4 yyy 2014-04-20 2014-04-21
now i have sql query like :
select * from leave where datefrom>='2014-05-01' and dateto<='2014-05-31'
so now i want output :
userid name total_leave_days
1 xxx 12
4 yyy 2
(2014-05-10 - 2014-05-15 )=6 days
(2014-05-20 - 2014-05-25 )=6 days
total = 12 days for useid 1
(2014-04-20 - 2014-04-21)= 2 days for userid 4
how can i calculate this total days .?

Answer 1

Please try:
select
USERID,
NAME,
SUM(DATEDIFF(day, DATEFROM, DATETO)+1) total_leave_days
From leave
group by USERID, NAME
SQL Fiddle Demo

Answer 2

It's important to note that you need "+1" to emulate the expected calculations because there is an inherent assumption of ""start of day" for the Start date and "end of day" for end date - but dbms's don't think that way. a date is always stored as "start of day".
select
USERID
, name
, sum( datediff(day,DATEFROM,DATETO) + 1 ) as leave_days
from leavetable
group by
USERID
, name
produces this:
| USERID | NAME | LEAVE_DAYS |
|--------|------|------------|
| 1 | xxx | 12 |
| 4 | yyy | 2 |
see: http://sqlfiddle.com/#!3/ebe5d/1

Answer 3

You can use DateDiff.
SELECT UserID, Name, SUM(DATEDIFF(DAY, DateFrom, DateTo) + 1) AS total_leave_days
FROM leave
WHERE datefrom >= '2014-05-01' AND dateto <= '2014-05-31'
GROUP BY UserID, Name
The + 1 ,of course, is because DATEDIFF will return the exclusive count, where it sounds like you want the inclusive number of days.

Answer 4

Try this:
select userid, name, sum (1 + datediff(day,datefrom,dateto)) as total_leave_days
from leaves
where datefrom>='2014-05-01' and dateto<='2014-05-31'
group by userid, name
This will sum the total leaves per userid. Note that datediff will give you 5 days difference for the range 2014-05-10 to 2014-05-15, so we need to add 1 to the result to get 6 days i.e. range inclusive of both ends.
Demo