Hello.
I'm learning couchdb and I'd appreciate if someone could have look and
comment on the code and description that follows.
Given a set of documents like {date:"2009-10-11", amount:10500}, I'm
using the view below
and group_level={1,2,3} to group by year, month or day and return the
average amount for each group.
I don't think it's possible to write a rereduce-friendly averaging
function; Instead, I return an object
that holds the total amount and the number of rows for each group.The
client has to calculate the average on his own.
_view/by_date?group_level=1 returns one row for each year, with the
average amount for that year
_view/by_date?group_level=2 returns one row for each mont, with the
average amount for that month
_view/by_date?group_level=3 returns one row for each day
//map.js:
function(doc) {
emit(doc.date.split('-'), doc.amount);
}
// reduce.js
function(keys, values, rereduce) {
if (rereduce) {
var result = {tot:0, count:0};
for (var idx in values) {
result.tot += values[idx].tot;
result.count += values[idx].count;
}
return result;
}
else {
var result = {tot:sum(values), count:values.length};
return result;
}
}
Thanks :)
--
:Matteo Caprari
[email protected]
