SQL Group by Month - group-by

Question

I have a table of Sales data with each line as a sale date mm/dd/yy.
I'm trying to create a query so I can see total sales for each month I have.
Would I have to create a column separate that dictates only the month? Or is there a way that it can take the month from that date format?

Answer 1

The short answer is: You don't need a separate column. You can group by the result of a function call.
The details of what that function might depend on your database, how you want results formatted, and performance considerations.
The following both work in Oracle:
SELECT extract(YEAR FROM ae.saledate), extract(MONTH FROM ae.saledate), count(*)
FROM mytable ae
GROUP BY extract(YEAR FROM ae.saledate), extract(MONTH FROM ae.saledate);
SELECT TO_CHAR(ae.saledate, 'YYYY-MM'), count(*)
FROM mytable ae
GROUP BY TO_CHAR(ae.saledate, 'YYYY-MM');
Edited to add versions that ignore year and only look at month (since I was making an assumption above that wasn't actually in the question):
SELECT extract(MONTH FROM ae.saledate), count(*)
FROM mytable ae
GROUP BY extract(MONTH FROM ae.saledate);
SELECT TO_CHAR(ae.saledate, 'MM'), count(*)
FROM mytable ae
GROUP BY TO_CHAR(ae.saledate, 'MM');

Answer 2

The following Query will helpful.
CREATE TABLE #TEMP
(SalesDate DATETime,
Amount float
)
INSERT INTO #TEMP
SELECT '2016-01-12', 12
UNION
SELECT '2016-01-13', 12
UNION
SELECT '2016-02-12', 12
UNION
SELECT '2016-03-12', 12
SELECT CONVERT(VARCHAR(7), SalesDate, 120) AS 'YYYY-MM',
SUM(Amount) as 'Amount'
FROM #Temp
GROUP BY CONVERT(VARCHAR(7), SalesDate, 120)
OUTPUT :
YYYY-MM Amount
------- ----------------------
2016-01 24
2016-02 12
2016-03 12
(3 row(s) affected)
For only Month Wise
SELECT RIGHT(CONVERT(VARCHAR(7), SalesDate, 120), 2) AS 'MM',
sum(Amount) as 'Amount'
from #Temp
group by RIGHT(CONVERT(VARCHAR(7), SalesDate, 120), 2)
Output:
MM Amount
---- ----------------------
01 24
02 12
03 12
(3 row(s) affected)