I currently have a Mongoid model in a Ruby on Rails application as such:
class Listen
include Mongoid::Document
field :song_title, type: String
field :song_artist, type: String
field :loc, :type => Array
field :listened_at, type: Time, default: -> { Time.now }
index(
[[:loc, Mongo::GEO2D]], background: true
)
end
When I try to query the collection for example
listens = Listen.where(:loc => {"$within" => {"$centerSphere" => [location, (radius.fdiv(6371))]}})
I am returned the error (locations have been blanked out, the X's are not returned)
Mongo::OperationFailure (can't find special index: 2d for: { loc: { $within: { $centerSphere: [ [ XX.XXXXXXX, X.XXXXXXX ], 0.0001569612305760477 ] } } }):
I know I can create the indexed through a rake task such as rake db:mongoid:create_indexes but I don't want to have to do this every time a model is created. Is there any way for the model to create this automatically on insert to the collection?
Nope there is no way.
You must create indexes (not just Geo) once, to use it.
Related
I have been struggling for a few days trying to get queries to work. At the moment my model looks like this:
class Geojson
include Mongoid::Document
field :type, type: String, default: 'Point'
field :coordinates, type: Array
index({coordinates: "2dsphere"}, { bits: 12})
end
The following query returns nil:
Geojson.find(:coordinates => {"$nearSphere" => [-70.1197340629727, 4.67071244438]})
These are the current instances in my database:
[#<Geojson _id: 61b7b21a9eb0c9ef0aa5626d, type: "Point", coordinates: [-74.13041168951031, 4.6638117]>,
#<Geojson _id: 61b7b2619eb0c9ef0aa5626e, type: "Point", coordinates: [-74.1213041168951, 4.5638117]>]
I am able to query similar cases on mongosh with no issues, however I am not sure where the mistake is when doing it directly on rails.
I finally managed to make it work the following way: (for a 2d sphere index)
Geojson.where(:coordinates => {"$nearSphere" => [long, lat]}).to_a
Where longitude and latitude are the parameters received.
Each user has one address.
class User
include Mongoid::Document
has_one :address
end
class Address
include Mongoid::Document
belongs_to :user
field :street_name, type:String
end
u = User.find(...)
u.address.update(street_name: 'Main St')
If we have a User without an Address, this will fail.
So, is there a good (built-in) way to do u.address.update_or_initialize_with?
Mongoid 5
I am not familiar with ruby. But I think I understand the problem. Your schema might looks like this.
user = {
_id : user1234,
address: address789
}
address = {
_id: address789,
street_name: ""
user: user1234
}
//in mongodb(javascript), you can get/update address of user this way
u = User.find({_id: user1234})
u.address //address789
db.address.update({user: u.address}, {street_name: "new_street name"})
//but since the address has not been created, the variable u does not even have property address.
u.address = undefined
Perhaps you can try to just create and attached it manually like this:
#create an address document, to get _id of this address
address = address.insert({street_name: "something"});
#link or attached it to u.address
u.update({address: address._id})
I had this problem recently. There is a built in way but it differs from active records' #find_or_initialize_by or #find_or_create_by method.
In my case, I needed to bulk insert records and update or create if not found, but I believe the same technique can be used even if you are not bulk inserting.
# returns an array of query hashes:
def update_command(users)
updates = []
users.each do |user|
updates << { 'q' => {'user_id' => user._id},
'u' => {'address' => 'address'},
'multi' => false,
'upsert' => true }
end
{ update: Address.collection_name.to_s, updates: updates, ordered: false }
end
def bulk_update(users)
client = Mongoid.default_client
command = bulk_command(users)
client.command command
client.close
end
since your not bulk updating, assuming you have a foreign key field called user_id in your Address collection. You might be able to:
Address.collection.update({ 'q' => {'user_id' => user._id},
'u' => {'address' => 'address'},
'multi' => false,
'upsert' => true }
which will match against the user_id, update the given fields when found (address in this case) or create a new one when not found.
For this to work, there is 1 last crucial step though.
You must add an index to your Address collection with a special flag.
The field you are querying on (user_id in this case)
must be indexed with a flag of either { unique: true }
or { sparse: true }. the unique flag will raise an error
if you have 2 or more nil user_id fields. The sparse option wont.
Use that if you think you may have nil values.
access your mongo db through the terminal
show dbs
use your_db_name
check if the addresses collection already has the index you are looking for
db.addresses.getIndexes()
if it already has an index on user_id, you may want to remove it
db.addresses.dropIndex( { user_id: 1} )
and create it again with the following flag:
db.addresses.createIndex( { user_id: 1}, { sparse: true } )
https://docs.mongodb.com/manual/reference/method/db.collection.update/
EDIT #1
There seems to have changes in Mongoid 5.. instead of User.collection.update you can use User.collection.update_one
https://docs.mongodb.com/manual/reference/method/db.collection.updateOne/
The docs show you need a filter rather than a query as first argument but they seem to be the same..
Address.collection.update_one( { user_id: user_id },
'$set' => { "address": 'the_address', upsert: true} )
PS:
If you only write { "address": 'the_address' } as your update clause without including an update operator such as $set, the whole document will get overwritten rather than updating just the address field.
EDIT#2
About why you may want to index with unique or sparse
If you look at the upsert section in the link bellow, you will see:
To avoid multiple upserts, ensure that the filter fields are uniquely
indexed.
https://docs.mongodb.com/manual/reference/method/db.collection.updateOne/
I have a model Event that is connected to MongoDB using Mongoid:
class Event
include Mongoid::Document
include Mongoid::Timestamps
field :user_name, type: String
field :action, type: String
field :ip_address, type: String
scope :recent, -> { where(:created_at.gte => 1.month.ago) }
end
Usually when I use ActiveRecord, I can do something like this to group results:
#action_counts = Event.group('action').where(:user_name =>"my_name").recent.count
And I get results with the following format:
{"action_1"=>46, "action_2"=>36, "action_3"=>41, "action_4"=>40, "action_5"=>37}
What is the best way to do the same thing with Mongoid?
Thanks in advance
I think you'll have to use map/reduce to do that. Look at this SO question for more details:
Mongoid Group By or MongoDb group by in rails
Otherwise, you can simply use the group_by method from Enumerable. Less efficient, but it should do the trick unless you have hundreds of thousands documents.
EDIT: Example of using map/reduce in this case
I'm not really familiar with it but by reading the docs and playing around I couldn't reproduce the exact same hash you want but try this:
def self.count_and_group_by_action
map = %Q{
function() {
key = this.action;
value = {count: 1};
emit(key, value);
# emit a new document {"_id" => "action", "value" => {count: 1}}
# for each input document our scope is applied to
}
}
# the idea now is to "flatten" the emitted documents that
# have the same key. Good, but we need to do something with the values
reduce = %Q{
function(key, values) {
var reducedValue = {count: 0};
# we prepare a reducedValue
# we then loop through the values associated to the same key,
# in this case, the 'action' name
values.forEach(function(value) {
reducedValue.count += value.count; # we increment the reducedValue - thx captain obvious
});
# and return the 'reduced' value for that key,
# an 'aggregate' of all the values associated to the same key
return reducedValue;
}
}
self.map_reduce(map, reduce).out(inline: true)
# we apply the map_reduce functions
# inline: true is because we don't need to store the results in a collection
# we just need a hash
end
So when you call:
Event.where(:user_name =>"my_name").recent.count_and_group_by_action
It should return something like:
[{ "_id" => "action1", "value" => { "count" => 20 }}, { "_id" => "action2" , "value" => { "count" => 10 }}]
Disclaimer: I'm no mongodb nor mongoid specialist, I've based my example on what I could find in the referenced SO question and Mongodb/Mongoid documentation online, any suggestion to make this better would be appreciated.
Resources:
http://docs.mongodb.org/manual/core/map-reduce/
http://mongoid.org/en/mongoid/docs/querying.html#map_reduce
Mongoid Group By or MongoDb group by in rails
I have the following array:
#unregistered_users = ['my#email.com', 'your#email.com', ...]
Now, I want to create a document for each array element:
#unregistered_users.each do |email_address|
Model.create(email: email_address, user: self.user, detail: self)
end
But it only creates a single document (the first element of the array). The other array elements are simply not created. Why?
We're using Ruby 1.9.3-p385, Rails 3.2.12, MongoID 3.0.0 and MongoDB 2.2.3
Update #1
So, we had a custom _id field with a custom random token using SecureRandom.hex(64).to_i(16).to_s(36)[0..127].
After I removed it worked normally, but with regular mongo ID's (which is not what we want).
Update #2
This is how the token are being generated:
class Model
include Mongoid::Document
include Mongoid::Timestamps
...
field :_id, default: SecureRandom.hex(64).to_i(16).to_s(36)[0..127]
...
index( { _id: 1 }, { unique: true } )
end
Try something like this to check what are the errors on the mongoid model:
#unregistered_users.each do |email_address|
model = Model.create(email: email_address, user: self.user, detail: self)
puts model.errors.inspect unless model.persisted?
end
or use create! to raise an exception and see what's happening
I'm trying to use Tire to perform a nested query on a persisted model. The model (Thing) has Tags and I'm looking to find all Things tagged with a certain Tag
class Thing
include Tire::Model::Callbacks
include Tire::Model::Persistence
index_name { "#{Rails.env}-thing" }
property :title, :type => :string
property :tags, :default => [], :analyzer => 'keyword', :class => [Tag], :type => :nested
end
The nested query looks like
class Thing
def self.find_all_by_tag(tag_name, args)
self.search(args) do
query do
nested path: 'tags' do
query do
boolean do
must { match 'tags.name', tag_name }
end
end
end
end
end
end
end
When I execute the query I get a "not of nested type" error
Parse Failure [Failed to parse source [{\"query\":{\"nested\":{\"query\":{\"bool\":{\"must\":[{\"match\":{\"tags.name\":{\"query\":\"TestTag\"}}}]}},\"path\":\"tags\"}},\"size\":10,\"from\":0,\"version\":true}]]]; nested: QueryParsingException[[test-thing] [nested] nested object under path [tags] is not of nested type]; }]","status":500}
Looking at the source for Tire it seems that mappings are created from the options passed to the "property" method, so I don't think I need a separate "mapping" block in the class. Can anyone see what I am doing wrong?
UPDATE
Following Karmi's answer below, I recreated the index and verified that the mapping is correct:
thing: {
properties: {
tags: {
properties: {
name: {
type: string
}
type: nested
}
}
title: {
type: string
}
}
However, when I add new Tags to Thing
thing = Thing.new
thing.title = "Title"
thing.tags << {:name => 'Tag'}
thing.save
The mapping reverts to "dynamic" type and "nested" is lost.
thing: {
properties: {
tags: {
properties: {
name: {
type: string
}
type: "dynamic"
}
}
title: {
type: string
}
}
The query fails with the same error as before. How do I preserve the nested type when adding new Tags?
Yes, indeed, the mapping configuration in property declarations is passed on in the Persistence integration.
In a situation like this, there's always the and and only first question: how does the mapping look like for real?
So, use eg. the Thing.index.mapping method or the Elasticsearch's REST API: curl localhost:9200/things/_mapping to have a look.
Chances are, that your index was created with the dynamic mapping, based on the JSON you have used, and you have changed the mapping later. In this case, the index creation logic is skipped, and the mapping is not what you expect.
There's a Tire issue opened about displaying warning when the index mapping is different from the mapping defined in the model.