Question

i want to use case condition for getting values between dates.

i have a table name user and a column date,i want to fetch the values from database using date condtion.

select sum(visitor) AS V FROM user  WHERE date  < '21-05-2012' AND dDateTime > '11-05-2012' 
select sum(visitor) AS c FROM user  WHERE date  < '21-06-2012' AND dDateTime > '11-06-2012'
select sum(visitor) AS s FROM user  WHERE date  < '21-07-2012' AND dDateTime > '11-07-2012'
select sum(visitor) AS g FROM user  WHERE date  < '21-08-2012' AND dDateTime > '11-08-2012'

how to make this whole query in a single statement.

Answer 1

Here’s an example of a sum with a case inside:

select sum(case when date < '21-05-2012' AND dDateTime > '11-05-2012' then visitor end) v 
,      sum(case when date < '21-06-2012' AND dDateTime > '11-06-2012' then visitor end) c
,      sum(case when date < '21-07-2012' AND dDateTime > '11-07-2012' then visitor end) s
,      sum(case when date < '21-08-2012' AND dDateTime > '11-08-2012' then visitor end) g
from   user