SQL Count Rows GROUP BY Month Name - sql

Question

I have a table and it has the following structure:
DEVICE_ID | DATE | STATUS
------------------------------------------
1 | 2021/01/05 | accepted
2 | 2021/01/23 | success
3 | 2021/02/07 | success
4 | 2021/03/11 | accepted
5 | 2021/03/20 | unsuccess
6 | 2021/03/26 | success
I want to calculate no of records in 2021 by status and GROUP BY month name like this :
MONTH | ACCEPTED | SUCCESS | UNSUCCESS
------------------------------------------------
January | 1 | 1 | 0
February | 0 | 1 | 0
March | 1 | 1 | 1
April | 0 | 0 | 0
May | 0 | 0 | 0
June | 0 | 0 | 0
July | 0 | 0 | 0
August | 0 | 0 | 0
September | 0 | 0 | 0
October | 0 | 0 | 0
November | 0 | 0 | 0
December | 0 | 0 | 0
Please help me to solve this issue

Answer 1

Explanation - because you want the full month list you need to be able to have all 12 months somewhere in the data. Then you want the custom status columns pivoted to display as you asked.
You should next time at least or tell us what you tried. It helps us figure out how youre thinking about it and how we can help you get past whatever roadblocks youve encountered.
IF OBJECT_ID('TempDb..#tmp') IS NOT NULL DROP TABLE #tmp;
IF OBJECT_ID('TempDb..#tmp2') IS NOT NULL DROP TABLE #tmp2;
CREATE TABLE #tmp
(
Device_ID INT
, Date VARCHAR(12)
, Status VARCHAR(15)
)
;
CREATE TABLE #tmp2
(
MOnthName VARCHAR(25)
)
;
INSERT INTO #tmp2
(MonthName)
VALUES
('January'),
('February'),
('March'),
('April'),
('May'),
('June'),
('July'),
('August'),
('September'),
('October'),
('November'),
('December')
;
INSERT INTO #tmp
(
Device_ID
, Date
, Status
)
VALUES
(1,'2021/01/05','accepted'),
(2,'2021/01/23','success'),
(3,'2021/02/07','success'),
(4,'2021/03/11','accepted'),
(5,'2021/03/20','unsuccess'),
(6,'2021/03/26','success')
;
SELECT
MOnthName
, success
, accepted
, unsuccess
FROM
(
SELECT
tt.MonthName
, Status
FROM
#tmp2 tt
LEFT JOIN #tmp t ON tt.MOnthName = DATENAME(month, CAST(Date AS DATE))
GROUP BY
tt.MonthName
, Status
) AS SourceTable
PIVOT
(
COUNT(Status) FOR Status IN ([accepted], [success], [unsuccess])
) AS PivotTable
ORDER BY
CASE
WHEN MonthName ='January' THEN 1
WHEN MonthName ='February' THEN 2
WHEN MonthName ='March' THEN 3
WHEN MonthName ='April' THEN 4
WHEN MonthName ='May' THEN 5
WHEN MonthName ='June' THEN 6
WHEN MonthName ='July' THEN 7
WHEN MonthName ='August' THEN 8
WHEN MonthName ='September' THEN 9
WHEN MonthName ='October' THEN 10
WHEN MonthName ='November' THEN 11
WHEN MonthName ='December' THEN 12
END

Answer 2

create table yourtable(DEVICE_ID int, DATE date, STATUS varchar(50));
insert into yourtable values(1, '2021/01/05' , 'accepted');
insert into yourtable values(2, '2021/01/23' , 'success');
insert into yourtable values(3, '2021/02/07' , 'success');
insert into yourtable values(4, '2021/03/11' , 'accepted');
insert into yourtable values(5, '2021/03/20' , 'unsuccess');
insert into yourtable values(6, '2021/03/26' , 'success');
Query:
;WITH months(MonthNumber) AS
(
SELECT 0
UNION ALL
SELECT MonthNumber+1
FROM months
WHERE MonthNumber < 11
)
SELECT DATENAME(MONTH,DATEADD(MONTH,MonthNumber,'01-01-2021')) AS [month],
coalesce(sum(case when status='ACCEPTED' then 1 end),0) ACCEPTED,
coalesce(sum(case when status='SUCCESS' then 1 end),0) SUCCESS,
coalesce(sum(case when status='UNSUCCESS' then 1 end),0) UNSUCCESS
FROM months m left join yourtable y
on m.monthnumber=month(y.[date])-1
group by monthnumber
Output:
month
ACCEPTED
SUCCESS
UNSUCCESS
January
1
1
0
February
0
1
0
March
1
1
1
April
0
0
0
May
0
0
0
June
0
0
0
July
0
0
0
August
0
0
0
September
0
0
0
October
0
0
0
November
0
0
0
December
0
0
0
db<>fiddle here