Date Comparison of Two Tables in SQL SERVER - sql-server

Question

I had this Data,
Table One :
EmpID Date Absent
1 01/01/2018 1
1 01/02/2018 1
1 02/05/2018 1
1 03/25/2018 1
1 04/01/2018 0
1 05/02/2018 1
1 06/03/2018 1
Table Two
ID Amount DateEffective
1 5.00 02/06/2018
2 3.00 05/02/2018
3 10.00 06/03/2018
Desired Output
EmpID Month Year Absent Penalty
1 January 2018 2 5.00
1 February 2018 1 5.00
1 March 2018 1 3.00
1 April 2018 0 3.00
1 May 2018 1 13.00
1 June 2018 1 10.00
This is my Code
SELECT { fn MONTHNAME(one.Date) } AS MonthName, YEAR(one.Date) AS Year, SUM(one.Absent) AS Absent,
(
SELECT top 1 two.DailyRate
FROM table_two as two
WHERE EmpID = '1'
AND one.Date <= two.EffectivityDate
)
FROM table_one as one
WHERE EmpID = '1'
GROUP BY { fn MONTHNAME(one.Date) }, MONTH(one.Date), YEAR(one.DTRDate)
ORDER BY Year(one.Date),month(one.Date)
and it shows an error :
Column 'one.Date' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause
please help for this issue...
Thanks

Answer 1

Try this :
SELECT
one.EmpID
,DATENAME(MONTH,one.Date) AS [MonthName]
,YEAR(one.Date) AS [Year]
,SUM(one.Absent) AS [Absent]
,(SELECT top 1 two.Amount
FROM table_two as two
WHERE two.ID = one.EmpID
AND YEAR(two.DateEffective) >= YEAR(one.Date)
AND MONTH(two.DateEffective) >=MONTH(one.Date)
) AS [Penalty]
FROM table_one as one
WHERE
one.EmpID = '1'
GROUP BY one.EmpID,DATENAME(MONTH,one.Date), MONTH(one.Date), YEAR(one.Date)
ORDER BY Year(one.Date),month(one.Date)

Answer 2

From my understanding to do this,
select e.EmpID
,datename(month,e.Date)[month]
,year(e.Date) [year]
,sum(e.Absent) as [Abscount]
,a.Amount
from
empl e left join abs a
on datename(month,e.Date)=DATENAME(month,a.DateEffective)
group by e.EmpID,DATENAME(MONTH,e.Date), MONTH(e.Date), YEAR(e.Date) , a.Amount
order by Abscount desc
Revert me if any clarifications needed...

Answer 3

is this helpful.?
Create Table #TabOne(EmpID int,[Date] Date,[Absent] Bit)
Create Table #TabTwo(ID int,Amount float,DateEffective Date)
Insert into #TabOne
SELECT 1,'01/01/2018',1 Union All
SELECT 1,'01/02/2018',1 Union All
SELECT 1,'02/05/2018',1 Union All
SELECT 1,'03/25/2018',1 Union All
SELECT 1,'04/01/2018',0 Union All
SELECT 1,'05/02/2018',1 Union All
SELECT 1,'06/03/2018',1
Insert into #TabTwo
Select 1,5.00 ,'02/06/2018' Union All
Select 2,3.00 ,'05/02/2018' Union All
Select 3,10.00,'06/03/2018'
;with cte1
As
(
Select One.EmpID,MONTH(one.[Date]) As [mon],YEAR(one.[Date]) As [Year],two.Amount,one.[Absent],
ROW_NUMBER() OVER(partition by One.EmpID,One.[Date] order by DATEDIFF(dd,two.DateEffective,one.[Date]) desc) as rn
from #TabOne one
LEFT JOIN #TabTwo two on one.[Date]<=two.DateEffective
)
Select EmpID,DATENAME(month, DATEADD(month, [mon]-1, CAST('2008-01-01' AS datetime))) As [Month],
[Year],SUM(CASE WHEN [Absent]=0 then 0 ELSE 1 END) As [Absent] ,MAX(Amount) As Penalty
from cte1
where rn=1
Group by EmpID,[Year],[mon]
order by EmpID,[Year],[mon]
Drop Table #TabOne
Drop Table #TabTwo