SQL Query AVG Date Time In same Table Column - sql

Question

I’m trying to make a query that returns the difference of days to get the average of days in a period of time. This is the situation I need to get the max date from the status 2 and the max date from the status 3 from a request and get how much time the user spend on that period of time
So far this is the query I Have right now I get the mas and min and the difference between the days but are not the max of the status 2 and the max of status 3
Query I have so far:
SELECT distinct t1.user, t1.Request,
Min(t1.Time) as MinDate,
Max(t1.Time) as MaxDate,
DATEDIFF(day, MIN(t1.Time), MAX(t1.Time))
FROM [Hst_Log] t1
where t1.Request = 146800
GROUP BY t1.Request, t1.user
ORDER BY t1.user, max(t1.Time) desc
Example table:
-------------------------------
user | Request | Status | Time
-------------------------------
User 1 | 2 | 1 | 6/1/15 3:25 PM
User 2 | 1 | 1 | 2/1/15 3:24 PM
User 2 | 3 | 1 | 2/1/15 3:24 PM
User 1 | 4 | 1 | 5/10/15 3:18 PM
User 3 | 3 | 2 | 5/4/15 2:36 PM
User 2 | 2 | 2 | 6/4/15 2:34 PM
User 3 | 2 | 3 | 6/10/15 5:51 PM
User 1 | 1 | 2 | 5/1/15 5:49 PM
User 3 | 4 | 2 | 5/16/15 2:39 PM
User 2 | 4 | 2 | 5/17/15 2:32 PM
User 2 | 3 | 2 | 4/6/15 2:22 PM
User 2 | 3 | 3 | 4/7/15 2:06 PM
-------------------------------
I will appreciate all the help

Answer 1

You'll need to use subqueries since the groups for the min and max times are different. One query will pull the min value where the status is 2. Another will pull the max value where the status is 3.
Something like this:
SELECT MinDt.[User], minDt.MinTime, MaxDt.MaxTime, datediff(d,minDt.MinTime, MaxDt.MaxTime) as TimeSpan
FROM
(SELECT t1.[user], t1.Request,
Min(t1.Time) as MinTime
FROM [Hst_Log] t1
where t1.Request = 146800
and t1.[status] = 2
GROUP BY t1.Request, t1.[user]) MinDt
INNER JOIN
(SELECT t1.[user], t1.Request,
Max(t1.Time) as MaxTime
FROM [Hst_Log] t1
where t1.[status] = 3
GROUP BY t1.Request, t1.[user]) MaxDt
ON MinDt.[User] = MaxDt.[User] and minDt.Request = maxDt.Request

Answer 2

something like this?
(mysql)
SELECT t.*,MAX(t.UFecha), x.*,y.*,Min(t.UFecha) as MinDate,
Max(t.UFecha) as MaxDate,
avg(x.Expr2+y.Expr3),//?????
DATEDIFF(MIN(t.UFecha), MAX(t.UFecha)) AS Expr1
FROM `app_upgrade_hst_log` t
left join(select count(*),Request, DATEDIFF(MIN(UFecha), MAX(UFecha)) AS Expr2 FROM `app_upgrade_hst_log` where Status=1 group by Request,Status) x on t.Request= x.Request
left join(select count(*),Request, DATEDIFF(MIN(UFecha), MAX(UFecha)) AS Expr3 FROM `app_upgrade_hst_log` where Status=2) y on t.Request= y.Request
group by t.Request,t.Status

Answer 3

What is the SQL-Server version? Maybe you could use your query as CTE and do a follow-up SELECT where you can use the Min and Max date as date period.
EDIT: Exampel
WITH myCTE AS
(
put your query here
)
SELECT * FROM myCTE
You can use myCTE for further joins too, pick out the needed date, use sub-select, what ever... AND: have a look on the OVER-link, could be helpfull...
Depending on the version you could also think about using OVER
https://msdn.microsoft.com/en-us/library/ms189461.aspx