CODEWITHSUNDEEP
pythonmongodb
thefonso
thefonso

Reputation: 3390

how to use aggregation in mongodb?

Mongo noob here.

Ok I have a collection of zips that are 30000 (approx) total.

they look like this...

{ "city" : "EPES", "loc" : [ -88.161443, 32.763371 ], "pop" : 1391, "state" : "AL", "_id" : "35460" }
{ "city" : "ETHELSVILLE", "loc" : [ -88.221987, 33.386816 ], "pop" : 719, "state" : "AL", "_id" : "35461" }
{ "city" : "EUTAW", "loc" : [ -87.930297, 32.888871 ], "pop" : 6586, "state" : "AL", "_id" : "35462" }
{ "city" : "FOSTERS", "loc" : [ -87.735688, 33.135859 ], "pop" : 2100, "state" : "AL", "_id" : "35463" }
{ "city" : "GAINESVILLE", "loc" : [ -88.271558, 32.908364 ], "pop" : 1051, "state" : "AL", "_id" : "35464" }
{ "city" : "GORDO", "loc" : [ -87.900504, 33.346917 ], "pop" : 4333, "state" : "AL", "_id" : "35466" }
{ "city" : "KNOXVILLE", "loc" : [ -87.791855, 32.982423 ], "pop" : 373, "state" : "AL", "_id" : "35469" }
{ "city" : "COATOPA", "loc" : [ -88.173592, 32.588509 ], "pop" : 6055, "state" : "AL", "_id" : "35470" }
{ "city" : "CYPRESS", "loc" : [ -87.615134, 32.978853 ], "pop" : 2659, "state" : "AL", "_id" : "35474" }
{ "city" : "NORTHPORT", "loc" : [ -87.591441, 33.283425 ], "pop" : 20114, "state" : "AL", "_id" : "35476" }

I need to find the state with the 4th most zip codes in it using aggregation...I have no Idea.

Any help is appreciated

Upvotes: 2

Views: 968

Answers (2)

Tarek Deeb
Tarek Deeb

Reputation: 81

//group by state, then find the total of zip codes in each state, sort by total number //of zip codes in descending order. Then use skip to skip the top 3 states and limit to 1

db.zips.aggregate([{$group:{_id:{state:"$state"},zips:{$sum:1}}}, {$sort:{zips:-1}}, {$skip:3}, {$limit:1}])

Upvotes: 2

thefonso
thefonso

Reputation: 3390

solution: 

db.zips.aggregate([ {$group:{_id:{state:"$state"},numberOfzipcodes:{$sum:1}}}, {$sort:{numberOfzipcodes:-1}}, {$limit:4}])

Upvotes: 4

Related Questions