Teradata Dates with a day and week - teradata

Question

I have a User, I have records with a Date Timestamp it includes Day hour second, I want to for each User to count the number of hours they were in the system per that day, calculating the first record of the day and the last record of the day, then I want to do this for the week, so Column 1 = # of hours I was in the system for the day, column 2 = number of hours I am in the system for that week.
I know there is a simple way to do this and I am over looking the simplest thing i think.
Assigned To: = End User
Start Date = Date and Time for the record,
some records have a start date and time,
some have a start date and an end date.
If first record is 8/2/2021 8:43:49 AM then this is the first record,
if the last record for that day is 8/2/2021 3:52:58 PM
Calculate the hours and minutes between first record and last record.
Task StartDate EndDate ASSIGNEDTO
Effectuation 8/2/2021 7:16 frank.author
Case Review 8/2/2021 7:36 8/2/2021 7:38 james.stevo
Manual Outreach 8/2/2021 7:38 8/2/2021 10:46 james.stevo
Effectuation 8/2/2021 7:54 frank.author
Case Review 8/2/2021 8:00 8/2/2021 8:22 james.stevo
Manual Outreach 8/2/2021 8:23 8/2/2021 10:46 james.stevo
Manual Outreach 8/2/2021 8:33 8/2/2021 10:47 james.stevo
Manual Outreach 8/2/2021 8:38 8/2/2021 10:47 james.stevo
Effectuation 8/2/2021 8:51 frank.author
Case Review 8/2/2021 9:04 james.stevo
Manual Outreach 8/2/2021 9:18 8/2/2021 13:10 james.stevo
Case Review 8/2/2021 9:30 james.stevo
Case Review 8/2/2021 9:53 james.stevo
Manual Outreach 8/2/2021 10:43 8/2/2021 20:50 james.stevo
Manual Outreach 8/2/2021 11:03 8/2/2021 20:50 james.stevo
Case Review 8/2/2021 11:06 james.stevo
Case Review 8/2/2021 11:07 james.stevo
Case Review 8/2/2021 11:14 james.stevo
Case Review 8/2/2021 11:38 james.stevo
Effectuation 8/2/2021 11:38 frank.author
Manual Outreach 8/2/2021 12:03 8/2/2021 20:51 james.stevo
Case Review 8/2/2021 12:07 james.stevo
Manual Outreach 8/2/2021 12:23 8/2/2021 20:51 james.stevo

Answer 1

I put the 3 tables together
and was trying to get the min and max for the user,
sometimes there are 3 records for a user,
min date would be first login or min date and last maxdate would be last logout
Select AssignedTo as UserID,
Cast((STARTDATE) as Date) as UpdateDatetime,
min(STARTDATE) as minDate,
max(ENDDATE) as MaxDate ,
(MaxDate) - (minDate) hour to minute as htm,
'WorkflowLog' as Source
From WorkflowLog
Where INTERNALID Is Not Null
and ENDDATE Is Not NULL
group by 1,2
Union All
---- Task Completed
Select CREATEDBY as UserID,
Cast((AUDITDATETIME) as Date) as UpdateDatetime,
min(AUDITDATETIME) as minDate,
max(AuditDateTime) as MaxDate ,
(MaxDate) - (minDate) hour to minute as htm,
'Audit' as Source
From Audit
Where INTERNALID Is Not Null
and AuditDateTime Is Not NULL
group by 1,2
Union All
--- Task and Queue completed
Select CurrentAssignedTo as UserID,
Cast((UpdateDatetime) as Date) as UpdateDatetime,
min(UpdateDatetime) as minDate,
max(UpdateDatetime) as MaxDate ,
(MaxDate) - (minDate) hour to minute as htm,
'CaseMetadata' as Source
From CaseMetadata
Where INTERNALID Is Not Null
and UpdateDatetime Is Not NULL
group by 1,2 Select UserID,
Cast(UpdateDatetime as date)as UpdateDatetime,
min(minDate) as minDate,
max(MaxDate) as MaxDate ,
(MaxDate) - (minDate) hour to minute as htm
From users_In_Out
group by 1,5,2

Answer 2

Based on this post and a similar on Database Administrators
select
AssignedTo
,cast(StartDate as date) -- for each day
,min(StartDate) as minDate
,max(EndDate) as MaxDate
,MaxDate - minDate hour to minute -- difference max-min
from myTable
group by 1,2
Edit based on your answer:
WITH users_In_Out AS
(
Select AssignedTo as UserID,
Cast((STARTDATE) as Date) as UpdateDatetime,
min(STARTDATE) as minDate,
max(ENDDATE) as MaxDate ,
(MaxDate) - (minDate) hour to minute as htm,
'WorkflowLog' as Source
From WorkflowLog
Where INTERNALID Is Not Null
and ENDDATE Is Not NULL
group by 1,2
Union All
---- Task Completed
Select CREATEDBY as UserID,
Cast((AUDITDATETIME) as Date) as UpdateDatetime,
min(AUDITDATETIME) as minDate,
max(AuditDateTime) as MaxDate ,
(MaxDate) - (minDate) hour to minute as htm,
'Audit' as Source
From Audit
Where INTERNALID Is Not Null
and AuditDateTime Is Not NULL
group by 1,2
Union All
--- Task and Queue completed
Select CurrentAssignedTo as UserID,
Cast((UpdateDatetime) as Date) as UpdateDatetime,
min(UpdateDatetime) as minDate,
max(UpdateDatetime) as MaxDate ,
(MaxDate) - (minDate) hour to minute as htm,
'CaseMetadata' as Source
From CaseMetadata
Where INTERNALID Is Not Null
and UpdateDatetime Is Not NULL
group by 1,2
)
Select UserID,
UpdateDatetime,
min(minDate) as minDate,
max(MaxDate) as MaxDate ,
max(MaxDate) - min(minDate) hour to minute as htm
From users_In_Out
group by 1,2
Of course, calculating htm and source in the UNIONs is not needed for the final Select and could be removed.