showing previous and current month data in table using mysql - mysql

Question

I am trying to show three different figures of the same column In a mysql query, I would like to keep one month static: April, so it would be a case like this I want to show The current month, the previous month and the static month of the year I'm working with, in this case let us stick with 2012
Example
Tablename:payment
id , pay_date, amount
1 2012-02-12 1000
2 2012-03-11 780
3 2012-04-15 890
4 2012-05-12 1200
5 2012-06-12 1890
6 2012-07-12 1350
7 2012-08-12 1450
So what I want to do is show the column amount for the month of April as I said I want to keep that row static: 890, the current month lets say the current month is August:1450 and the previous month amount which would be July:1350: so the final result would be something like this:
april_amount current_month_amount previous_month_amount
890 1450 1350
However I'm stuck here:
select amount as april_amount
from payment
where monthname(pay_date) LIKE 'April'
and year(pay_date) LIKE 2012
I hope the question is written clear enough, and thanks alot for the help much appreciated.

Answer 1

If the results can be rows instead of columns:
SELECT MONTHNAME(pay_date), amount FROM payment
WHERE pay_date BETWEEN '2012-04-01'
AND '2012-04-30'
OR pay_date BETWEEN CURRENT_DATE
- INTERVAL DAYOFMONTH(CURRENT_DATE) - 1 DAY
AND LAST_DAY(CURRENT_DATE)
OR pay_date BETWEEN CURRENT_DATE
- INTERVAL DAYOFMONTH(CURRENT_DATE) - 1 DAY
- INTERVAL 1 MONTH
AND LAST_DAY(CURRENT_DATE - INTERVAL 1 MONTH)
See it on sqlfiddle.

Answer 2

I might be way off here. But try:
select top 1
p.amount, c.amount, n.amount
from payment c
inner join payment p ON p.pay_date < c.pay_date
inner join payment n ON n.pay_date > c.pay_date
where monthname(c.paydate) LIKE 'April'
and year(c.pay_date) LIKE 2012
order by p.pay_date DESC, n.pay_date ASC
EDIT, I didnt read your question properly. I was going for previous, current, and next month. 1 minute and I'll try again.
select top 1
p.amount AS april_amount, c.amount AS current_month_amount, n.amount AS previous_month_amount
from payment c
inner join payment p ON monthname(p.pay_date) = 'April' AND year(p.pay_date) = 2012
inner join payment n ON n.pay_date > c.pay_date
where monthname(c.paydate) = monthname(curdate())
and year(c.pay_date) = year(curdate())
order by n.pay_date ASC
This assumes there is only 1 entry per month.
Ok, so i haven't written in mysql for a while. here is what worked for your example data:
select
p.amount AS april_amount, c.amount AS current_month_amount, n.amount AS previous_month_amount
from payment AS c
inner join payment AS p ON monthname(p.pay_date) LIKE 'April' AND year(p.pay_date) LIKE 2012
inner join payment AS n ON n.pay_date < c.pay_date
where monthname(c.pay_date) LIKE monthname(curdate())
and year(c.pay_date) LIKE year(curdate())
order by n.pay_date DESC
limit 1
the previous month table joined is counterintuitively named n, but this works. I verified it in a WAMP install.
To handle aggregates per month you can use subselects. Performance may suffer on very large tables (millions of rows or more).
SELECT SUM( a.amount ) AS april_amount,
(
SELECT SUM( c.amount )
FROM payment c
WHERE MONTH( c.pay_date ) = MONTH( CURDATE( ) )
) AS current_month_amount,
(
SELECT SUM( p.amount )
FROM payment p
WHERE MONTH( p.pay_date ) = MONTH( CURDATE( ) - INTERVAL 1
MONTH )
) AS previous_month_amount
FROM payment a
WHERE MONTHNAME( a.pay_date ) = 'April'
AND YEAR( a.pay_date ) =2012