How do I count a Date Column based on another Date Column? - sql

Question

What I'm trying to achieve is to count the login attempts of a user based on the LoginAttempts value and on the LastLoginDate. For example, I need to query the LastLoginDate within 30 days with 2 Loginattempts.
result should be:
What I have is this..I created temp table to pull the information and and it doesn't seem to be counting correctly. Here's where I'm stuck..Any help would be appreciated!!

Answer 1

Your GROUP BY is incorrect. It includes LastLoginDateUTC. Consequently, you're counting logins per date, not logins per 30 days.
Drop LastLoginDateUTC from your GROUP BY, and change the SELECT clause to use max(LastLoginDateUTC) as LastLoginDateUTC. That should give you what you want.

Answer 2

Not sure if I understand your request completely, but here's something outside the box. Good luck!:
select FirstName, StudentID, UserName, LastLoginDate, LoginAttempts,
RowNumber = row_number() over(partition by StudentID order by StudentID, LoginAttempts)
into #temp1
from user
where cast(LastLoginDate as date) >= getdate()- 30
--should return all rows of data for past 30 days.
--should also rank each loginAttempt by student
select * from #temp1
where RowNumber >= 3

Answer 3

This not an answer... more a suggestion.
As I see it you have Students and you need to audit login attempts.
This for me is a one to many relation.
So I would keep the Student table, stripped off from any login related data.
This would simplify your Student table, keep less rows and save storage space for not using the same data (name, username, etc) over and over again.
That data would be in a StudentLoginAttempts, something like:
Create Table StudentLoginAttempts (
Id int not null identity(1,1),
StudentId int not null,
LoginDate datetime not null,
Successful bit not null,
Constraint PK_StudentLoginAttempts Primary Key Clustered (Id),
Constraint FK_StudentLoginAttempts_Student Foreign Key (StudentId) References Student(StudentId)
)
go
Create Index IX_StudentLoginAttempts_StudentId On StudentLoginAttempts(StudentId)
go
Create Index IX_StudentLoginAttempts_LoginDate On StudentLoginAttempts(LoginDate)
go
So things could be more clear and you can have more info.
Think the example bellow:
Create Table #Student (
StudentId int not null identity(1,1),
Username varchar(50) not null,
FirstName varchar(50) not null
)
Create Table #StudentLoginAttempts (
Id int not null identity(1,1),
StudentId int not null,
LoginDate datetime not null,
Successful bit not null
)
insert into #Student values
( 'Student001', 'JON' ),
( 'Student002', 'STEVE' )
insert into #StudentLoginAttempts values
( 1, '2016-01-01 09:12', 0 ),
( 1, '2016-02-01 09:12', 0 ),
( 1, '2016-03-01 09:12', 1 ),
( 2, '2016-03-02 10:12', 0 ),
( 2, '2016-04-02 10:12', 1 ),
( 2, '2016-05-02 10:12', 0 )
;with TotalAttemptsCte as (
select StudentId, TotalLoginAttempts = count(*) from #StudentLoginAttempts group by StudentId
),
FailedCte as (
select StudentId, FailedLogins = count(*) from #StudentLoginAttempts where ( Successful = 0 ) group by StudentId
),
SuccessfulCte as (
select StudentId, SuccessfulLogins = count(*) from #StudentLoginAttempts where ( Successful = 1 ) group by StudentId
),
LastSuccessFulDateCte as (
select StudentId, max(LoginDate) as LastSuccessfulLoginDate
from
#StudentLoginAttempts
where
( Successful = 1 )
group by StudentId
)
select
a.*, b.TotalLoginAttempts, c.FailedLogins, d.SuccessfulLogins, e.LastSuccessfulLoginDate
from
#Student a
left join TotalAttemptsCte b on ( a.StudentId = b.StudentId )
left join FailedCte c on ( a.StudentId = c.StudentId )
left join SuccessfulCte d on ( a.StudentId = d.StudentId )
left join LastSuccessFulDateCte e on ( a.StudentId = e.StudentId )
Drop Table #StudentLoginAttempts
Drop Table #Student
You could also create a view based on the query for more easy access.
I remind you that this is just a suggestion, how I would do it.