-- CREATE TABLE STATEMENT

create table log (
	id		int(11)		not null auto_increment,
	event_id	int(11)		not null,
	num		tinyint(1)	not null, -- will be either 1 or -1
	tstamp		date		not null,
	
	primary key (id),
	-- WHAT SHOULD MY INDEXES BE, CONSIDERING THE SELECT STATEMENT BELOW?
	
) engine = innodb ;

-- TABLE DATA

id | event_id | num | tstamp
---+----------+-----------------
 1 |     1    |  1  | 2007-06-06
 2 |     1    |  1  | 2007-06-06
 3 |     1    |  -1 | 2007-06-06
 4 |     1    |  1  | 2007-06-06
 5 |     1    |  1  | 2007-06-06 -- totals 3 for 2007-06-06
 6 |     1    |  1  | 2007-06-07
 7 |     1    |  1  | 2007-06-07
 8 |     1    |  1  | 2007-06-07
 9 |     1    |  -1 | 2007-06-07 -- totals 2 for 2007-06-07


-- SELECT STATEMENT
-- PRODUCES:  2007-06-06 | 3
              2007-06-07 | 2
select
	tstamp as date,
	sum(num) as total_num
from
	log
where
	event_id=1 and (tstamp > current_date()-5)
group by
	tstamp