Using MySQL Pivot Table Queries for a Monthly Attendance Report - mysql

Question

I have used pivot query for monthly report..
My table is like this:
CREATE TABLE IF NOT EXISTS `attendance` (
`empID` int(11) NOT NULL,
`date` date NOT NULL,
`deptID` int(11) NOT NULL,
`attStatus` varchar(3) NOT NULL,
PRIMARY KEY (`empID`,`date`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1;
For monthly attendance report, I have used this query:
SELECT empID,
GROUP_CONCAT(if(DAY(`date`) = 1, `attStatus`, NULL)) AS 'day1',
GROUP_CONCAT(if(DAY(`date`) = 2, `attStatus`, NULL)) AS 'day2',
GROUP_CONCAT(if(DAY(`date`) = 3, `attStatus`, NULL)) AS 'day3',
GROUP_CONCAT(if(DAY(`date`) = 4, `attStatus`, NULL)) AS 'day4',
GROUP_CONCAT(if(DAY(`date`) = 5, `attStatus`, NULL)) AS 'day5',
GROUP_CONCAT(if(DAY(`date`) = 6, `attStatus`, NULL)) AS 'day6',
GROUP_CONCAT(if(DAY(`date`) = 7, `attStatus`, NULL)) AS 'day7',
GROUP_CONCAT(if(DAY(`date`) = 8, `attStatus`, NULL)) AS 'day8',
GROUP_CONCAT(if(DAY(`date`) = 9, `attStatus`, NULL)) AS 'day9',
GROUP_CONCAT(if(DAY(`date`) = 10, `attStatus`, NULL)) AS 'day10',
GROUP_CONCAT(if(DAY(`date`) = 11, `attStatus`, NULL)) AS 'day11',
GROUP_CONCAT(if(DAY(`date`) = 12, `attStatus`, NULL)) AS 'day12',
GROUP_CONCAT(if(DAY(`date`) = 13, `attStatus`, NULL)) AS 'day13',
GROUP_CONCAT(if(DAY(`date`) = 14, `attStatus`, NULL)) AS 'day14',
GROUP_CONCAT(if(DAY(`date`) = 15, `attStatus`, NULL)) AS 'day15',
GROUP_CONCAT(if(DAY(`date`) = 16, `attStatus`, NULL)) AS 'day16',
GROUP_CONCAT(if(DAY(`date`) = 17, `attStatus`, NULL)) AS 'day17',
GROUP_CONCAT(if(DAY(`date`) = 18, `attStatus`, NULL)) AS 'day18',
GROUP_CONCAT(if(DAY(`date`) = 19, `attStatus`, NULL)) AS 'day19',
GROUP_CONCAT(if(DAY(`date`) = 20, `attStatus`, NULL)) AS 'day20',
GROUP_CONCAT(if(DAY(`date`) = 21, `attStatus`, NULL)) AS 'day21',
GROUP_CONCAT(if(DAY(`date`) = 22, `attStatus`, NULL)) AS 'day22',
GROUP_CONCAT(if(DAY(`date`) = 23, `attStatus`, NULL)) AS 'day23',
GROUP_CONCAT(if(DAY(`date`) = 24, `attStatus`, NULL)) AS 'day24',
GROUP_CONCAT(if(DAY(`date`) = 25, `attStatus`, NULL)) AS 'day25',
GROUP_CONCAT(if(DAY(`date`) = 26, `attStatus`, NULL)) AS 'day26',
GROUP_CONCAT(if(DAY(`date`) = 27, `attStatus`, NULL)) AS 'day27',
GROUP_CONCAT(if(DAY(`date`) = 28, `attStatus`, NULL)) AS 'day28',
GROUP_CONCAT(if(DAY(`date`) = 29, `attStatus`, NULL)) AS 'day29',
GROUP_CONCAT(if(DAY(`date`) = 30, `attStatus`, NULL)) AS 'day30',
GROUP_CONCAT(if(DAY(`date`) = 31, `attStatus`, NULL)) AS 'day31',
COUNT(if(`attStatus`='P', `attStatus`, NULL)) AS 'totalP'
FROM `attendance`
WHERE deptID=1 AND `date` BETWEEN '2011-07-01' AND '2011-07-31'
GROUP BY empID
So my question is, isn't this query too long?
Is there any alternative to this query to display monthly attendance report ?
If this query is okay then for those months which have 30 days in it, result for 31 days is displayed. Is there any solution to this?
UPDATE:
Here is a screenshot which explain what type of report I want:

Answer 1

No idea if your original query would work but something like this would be simpler:
select DAY(date),count(*) from attendance where MONTH(date) = 2 group by DAY(date);
That should get the attendance for February. The output would be:
+-----------+----------+
| DAY(date) | count(*) |
+-----------+----------+
| 18 | 1 |
| 19 | 2 |
+-----------+----------+

Answer 2

First, create a help table:
CREATE TABLE days
( d TINYINT PRIMARY KEY
) ;
INSERT INTO days
VALUES
(0), (1), (2), ..., (31) ;
Then you can try this. It will return less columns than your query though:
SELECT
a.empID
, GROUP_CONCAT( CASE WHEN a.attStatus IS NULL
THEN 'N'
ELSE a.attStatus
END
ORDER BY dates.dateCheck)
AS days
, COUNT( CASE WHEN a.attStatus='P' THEN 1 END )
AS totalP
FROM
( SELECT monthStart + INTERVAL d DAY
AS dateCheck
FROM days
CROSS JOIN
( SELECT '2011-07-01' AS monthStart
) AS m
WHERE MONTH(monthStart + INTERVAL d DAY) = MONTH(monthStart)
) AS dates
LEFT JOIN attendance AS a
ON a.`date` = dates.dateCheck
WHERE a.deptID = 1
GROUP BY a.empID