Dates by quarter - sql

Question

I would like to count number of birthdays by quarters in SQL Server
i.e. Between Jan 1 - March 31, April 1 - June 30, July 1 - Sep 30 & Oct 1 - Dec 31.
Please help me with the Date function in Sql Server to do this.
I pass BDate as DATETIME . I want to use this BDate to populate 4 fields of type int with counts for number of birthdays in each quarter.
Thanks.

Answer 1

As long as your "BDate" column is datetime, you can achieve this quite easily using this query:
SELECT DATEPART(QUARTER,BDATE), COUNT(*)
FROM TABLE1
GROUP BY DATEPART(QUARTER,BDATE)
ORDER BY DATEPART(QUARTER,BDATE) ASC
Here's a working fiddle using some random data: http://sqlfiddle.com/#!6/7734b/1

Answer 2

Data set up:
create table test (
d1 varchar(10),
d2 datetime
);
insert into test (d1,d2) values ('2015-01-28','2015-01-28');
insert into test (d1,d2) values ('2015-02-13','2015-02-13');
insert into test (d1,d2) values ('2015-07-19','2015-07-19');
insert into test (d1,d2) values ('2015-11-04','2015-11-04');
If you just want to get counts for each of the quarters present in your data:
select DATEPART(QUARTER, d2), count(*)
from test
group by DATEPART(QUARTER, d2);
You can use d1 or d2 (SQL Server will handle the varchar or datetime properly).
If you want to include all four quarters, even if they're not present in your data:
select qs.q, count(t.d2) as c
from (
SELECT 1 as q
UNION ALL
SELECT 2 as q
UNION ALL
SELECT 3 as q
UNION ALL
SELECT 4 as q) qs
left join test t
on qs.q = DATEPART(QUARTER, t.d2)
group by qs.q;
Again, you can use either d1 or d2, it doesn't matter. The "qs" query just gets the numbers 1 to 4, then that is outer joined to the table with the birth dates.

Answer 3

Please try this:
--replace '19000102' with your int column
select SUM(CASE WHEN DATEPART(MONTH,CONVERT (datetime,convert(char(8),19000102)))
IN (1,2,3)
THEN 1
ELSE 0
END) as 'Q1',
SUM(CASE WHEN DATEPART(MONTH,CONVERT (datetime,convert(char(8),19000102)))
IN (4,5,6)
THEN 1
ELSE 0
END) as 'Q2',
SUM(CASE WHEN DATEPART(MONTH,CONVERT (datetime,convert(char(8),19000102)))
IN (7,8,9)
THEN 1
ELSE 0
END) as 'Q3',
SUM(CASE WHEN DATEPART(MONTH,CONVERT (datetime,convert(char(8),19000102)))
IN (10,11,12)
THEN 1
ELSE 0
END) as 'Q4'