Setting null values to dates that aren't in MySQL - php

Question

So, I am fetching some data from MySQL with that code:
<?
$query=mysql_query("SELECT date,COUNT(*) as num FROM downloads WHERE prjID='".$_GET['id']."' GROUP BY date ORDER BY date ASC");
$num=mysql_num_rows($query);
$res='';
$i=0;
while($row=mysql_fetch_array($query)){
$i++;
$date=date("d.m.Y", strtotime($row['date']));
$dan=date("d", strtotime($row['date']));
$mesec=date("m", strtotime($row['date']));
$leto=date("Y", strtotime($row['date']));
if($i=1){
$danPrvi=$leto.", ".($mesec-1).", ".$dan;
$dan1=date("d", strtotime(time()));
$mesec1=date("m", strtotime(time()));
$leto1=date("Y", strtotime(time()));
$danZadnji=$leto1.", ".($mesec1-1).", ".$dan1;
}
$numb=1;
if($row['num']!=1){
$res.="[Date.UTC(".$leto.",".($mesec-1).",".$dan."),".$row['num']."], ";
}
else{
if($i!=$num){
$res.="[Date.UTC(".$leto.",".($mesec-1).",".$dan."),".$numb."], ";
}
else{
$res.="[Date.UTC(".$leto.",".($mesec-1).",".$dan."),".$numb."]";
}
}
}
?>
And I get results like that:
1.3.2013 - 1
6.3.2013 - 5
But I would like to get results like that:
1.3.2013 - 1
2.3.2013 - 0
3.3.2013 - 0
4.3.2013 - 0
5.3.2013 - 0
6.3.2013 - 1
I am also using Highcharts, so date values must be formatted like Date.UTC(year, month-1, day)
EDIT:
I don't have all dates in my databases. In my examle, there are only 1.3.2013 and 6.3.2013, so how would I detect and set 0 value for all dates between, that don't have a value >=1?

Answer 1

I imagine what you need to do is set up a construct to hold the dates you are interested in and either use that in your query or post processing the query data. For example:
<?php
$query=mysql_query("SELECT date,COUNT(*) as num FROM downloads WHERE prjID='".$_GET['id']."' GROUP BY date ORDER BY date ASC");
$num=mysql_num_rows($query);
// Get the first and last dates in the result set
$firstRow = mysql_result($query, 0);
$lastRow = mysql_result($query, $num-1);
// Now make thos the begin and end dates
$beginDate = new DateTime(strtotime($firstRow['date']));
$endDate = new DateTime(strtotime($lastRow['date']));
$currentDate = $beginDate;
$interestingDates = array();
// Populate our interestingDates array with all counts set to 0
while ($currentDate <= $endDate){
$interestingDates[$currentDate->format('d.m.Y')] = 0;
$currentDate->add(new DateInterval('P1D'));
}
// Reset the data result for looping over
mysql_data_seek($query,0);
while($row=mysql_fetch_array($query)){
// Go ahead and format the string
$formatedString = date("d.m.Y", strtotime($row['date']));
// If the string is in our interestingDates array, update the count
if (array_key_exists($formatedString, $interestingDates)){
$interestingDates[$formatedString] = $row['num'];
}
}
// Print it out
foreach ($interestingDates as $key=>$value){
print "$key - $value\n";
}
NOTE 1: mysql_query is deprecated as of PHP 5.5.0 and will be removed in the future. Pleasue use another API - I recommend pdo_mysql.
NOTE 2: The current query is not parameterized. Using PDO, this would perhaps look like:
$sth = $dbh->prepare('SELECT date,COUNT(*) as num FROM downloads WHERE prjID= :prjID GROUP BY date ORDER BY date ASC');
$sth->bindParam(':prjID', $_GET['id'], PDO::PARAM_INT);
$sth->execute();
Disclaimer - I haven't actually run this code, I just wrote it off the top of my head. You might need to test/debug it.

Answer 2

Assuming you have data for all dates, just not for a particular id, you can do a condition sum:
SELECT date, sum(case when prjID='".$_GET['id']."' then 1 else 0 end) as num
FROM downloads
GROUP BY date
ORDER BY date ASC

Answer 3

WARNING! It's a very bad style to do it in SQL, but if you want -- you can :)
http://sqlfiddle.com/#!2/b491a/1/0
SELECT dynamic_date AS date, COUNT(downloads.date) AS num FROM (
SELECT DATE_ADD(start, INTERVAL i - 1 DAY) AS dynamic_date, prjID FROM
(
SELECT #i := #i + 1 AS i FROM
(SELECT 0 UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) t1,
(SELECT 0 UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) t2,
(SELECT 0 UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) t3,
(SELECT #i:=0) init
) i_sequence,
(SELECT MIN(date) start, MAX(date) finish, prjID FROM downloads WHERE prjID=5 GROUP BY prjID) minmax
WHERE DATE_ADD(start, INTERVAL i - 1 DAY) <= finish
) date_sequence
LEFT JOIN downloads ON dynamic_date = downloads.date and downloads.prjID=date_sequence.prjID
GROUP BY dynamic_date
;