With couchbase, how to sum total by day - couchbase

Question

I am looking to total (sum) equipment used by day. The data i have is {job, toDate, fromDate, equipmentUsed}. Would mapreduce be the best and how would i do that with the "to" and "from" dates?
Here is some background. We have many projects. Many workorders for each projects. Workorders are by day and have inventory for that day. i want to sum the inventory for each day in a date range to see if we will run out of inventory.
I will post sample data shortly
{“project::100”: {“name”: “project one”}
,“project::101”: {“name”: “project two”}
,”workOrder::1000”: {“project”: “project::100”, “dateNeeded”: jan 1, “inventory”: [“equip1”: 2, “equip2”: 1, “equip3”: 3 , “equip4”: 4]}
,”workOrder::1001”: {“project”: “project::100”, “dateNeeded”: jan 2, “inventory”: [“equip1”: 1 , “equip2”: 2 , “equip3”: 1 , “equip4”: 4]}
,”workOrder::1002”: {“project”: “project::100”, “dateNeeded”: jan 4, “inventory”: [“equip1”: 1, “equip2”: 2, “equip3”: 3, “equip4”: 1 ]}
,”workOrder::1000”: {“project”: “project::101”, “dateNeeded”: jan 1, “inventory”: [“equip1”: 1, “equip2”: 3, “equip4”: 1]}
,”workOrder::1001”: {“project”: “project::101”, “dateNeeded”: jan 3, “inventory”: [ “equip2”: 1, “equip3”: 3 , “equip4”: 1]}
,”workOrder::1002”: {“project”: “project::101”, “dateNeeded”: jan 4, “inventory”: [“equip1”: 1, “equip2”: 1, “equip3”: 2 , “equip4”: 3]}
}

Answer 1

Can you give an example of what exactly you want? Looks like you want to consider aggregating equipUsed for the overlapping dates, as well as gaps in the date ranges etc. For ex:
{J1, Jan 7, Jan 1, 4},
{J2, Jan 4, Jan 2, 7},
{J3, Jan 10, Jan 5, 10},
{J4, Jan 25, Jan 15, 20} etc.,
The output is:
{Jan 1, 4}, {Jan2, 11 /4 + 7/}, {Jan 3, 11}, {Jan4, 11}, {jan 5, 14 /4+10/}, {Jan 6, 14}, {Jan 7, 14}, {Jan 8, 10}, {Jan 9, 10}, {Jan 10, 10}, {Jan 11 to 14th, 0}, and {Jan 15th to 25th, 20} etc.,
This is some non-trivial logic. You can use N1QL API with some programming language (java, python, node etc) to solve this. For example, an exhaustive algorithm in pseudo code is (assuming docs in 'default' bucket):
minDate = Run_N1QLQuery("SELECT MIN(fromDate} from default");
maxDate = Run_N1QLQuery("SELECT MAX(toDate) from default");
for d = minDate to maxDate
sum_used = Run_N1QLQuery("SELECT SUM(equipUsed) from default WHERE %s BETWEEN fromDate AND toDate", d);
d = increment_date(d);
Depending on what is exactly needed, one can write much more efficient algorithm.
hth,
-Prasad