converting mongo map reduce code to php - mongodb

Question

I have the following mongo shell code that I'm trying to use in my php application.
It's basically taking 800 evenly distributed values over a time frame, for use in a graph.
var map = function () {
if (endTime < 0) {
var start = new ISODate("2013-09-01T00:00:00.000Z");
var end = new ISODate("2013-11-01T00:00:00.000Z");
var startMilli = start.getTime();
var endMilli = end.getTime();
var interval = endMilli - startMilli;
delta = interval / 800;
endTime = startMilli + delta;
}
if (endTime < this.date.getTime()) {
resArray = {};
while (endTime < this.date.getTime()) {
endTime += delta;
}
}
var id = this.homeId + this.sensor;
if (typeof resArray[id] == 'undefined') {
resArray[id] = 1;
emit({
homeId: this.homeId,
sensor: this.sensor,
date: this.date,
val: this.val
}, {
x: 1
});
}
};
var reduce = function (key, values) {
return values[0];
};
db.passiv.mapReduce(
map,
reduce,
{ query:
{ homeId: 35600,
sensor : {
$in :[ "z1t","ts1"]
},
date : {
$gte : new ISODate("2013-09-01T00:00:00.000Z"),
$lte : new ISODate("2013-11-01T00:00:00.000Z")
} },
scope : {
resArray : {},
delta : -1,
endTime : -1
},
out: 'TEST1',
sort : {
date:1
}
});
It execute fine in the shell but my attempt to convert it to php is not giving me any results:
$from = '2013-09-01T00:00:00.000Z';
$to = '2013-11-01T00:00:00.000Z';
$map = new MongoCode("
var map = function () {
if (endTime < 0) {
var start = new ISODate(".$from.");
var end = new ISODate(".$to.");
var startMilli = start.getTime();
var endMilli = end.getTime();
var interval = endMilli - startMilli;
delta = interval / 800;
endTime = startMilli + delta;
}
if (endTime < this.date.getTime()) {
resArray = {};
while (endTime < this.date.getTime()) {
endTime += delta;
}
}
var id = this.homeId + this.sensor;
if (typeof resArray[id] == 'undefined') {
resArray[id] = 1;
emit({
homeId: this.homeId,
sensor: this.sensor,
date: this.date,
val: this.val},
{ x: 1 });
}
};");
$reduce = new MongoCode('
var reduce = function (key, values) {
return values[0];
};');
$constraint = array('homeId' => 32168);
$date = array('$gte' => new MongoDate(1377986400), '$lt' => new MongoDate(1383260400));
$condition = array_merge($constraint, $date, array("sensor" => array('$in' => array('z1t', 'ts1'))));
$rs = $passivCollection->command(
array(
"mapreduce" => "passiv",
"query" => $condition,
"map" => $map,
"reduce" => $reduce,
"scope" => array(
"resArray" => array(),
"delta" => -1,
"endTime" => -1
),
"out" => "TEST1",
"sort" => array("date" => 1)
));
Somehow I think it's the scope in the command at the end that's not working properly and I cant seem to find anything useful on the scope aspect anywhere. Any help is greatly appreciated.

Answer 1

A good example of doing Map Reduce in PHP is located here: http://php.net/manual/en/mongodb.command.php at example #3.
Basically one of the problems you have is that the MongoCode objects do not represent anon functions anymore but instead a variable that cannot be returned.
Instead you want to define your functions like:
$reduce = new MongoCode('
function (key, values) {
return values[0];
};
');
That should fix it I think.
edit
There is a problem with your PHP in the your edit:
$start = new MongoDate(strtotime("2013-09-01 00:00:00"));
$end = new MongoDate(strtotime("2013-11-01 00:00:00"));
$constraint = array('homeId' => '32168');
$date = array('$gte' => $start, '$lt' => $end);
$sensors = array('z1t');
$condition = array_merge($constraint, $date, array("sensor" => array('$in' => $sensors)));
var_dump($condition);
$tt = $passivCollection->selectCollection('passiv')->count($date);
var_dump($tt);
You are using:
$date = array('$gte' => $start, '$lt' => $end);
Without defining a field it should search on. Try:
$start = new MongoDate(strtotime("2013-09-01 00:00:00"));
$end = new MongoDate(strtotime("2013-11-01 00:00:00"));
$constraint = array('homeId' => '32168');
$date = array('date' => array('$gte' => $start, '$lt' => $end));
$sensors = array('z1t');
$condition = array_merge($constraint, $date, array("sensor" => array('$in' => $sensors)));
var_dump($condition);
$tt = $passivCollection->selectCollection('passiv')->count($date);
var_dump($tt);
Where the date string in:
$date = array('date' => array('$gte' => $start, '$lt' => $end));
is replaced by your field name.