mongo v0.5.0 → Overview → Mongo → Collection

Mongo.Collection

Module holding operations that can be performed on a collection (find, count…)

Usage:

iex> Mongo.Helpers.test_collection("anycoll") |> Mongo.Collection.count
{:ok, 6}

count() or count!()

The first returns {:ok, value}, the second returns simply value when the call is sucessful. In case of error, the first returns %Mongo.Error{} the second raises a Mongo.Bang exception.

iex> collection = Mongo.Helpers.test_collection("anycoll")
...> {:ok, 6} = collection |> Mongo.Collection.count
...> 6 === collection |> Mongo.Collection.count!
true

iex> collection = Mongo.Helpers.test_collection("anycoll")
...> {:ok, 2} = collection |> Mongo.Collection.count(a: ['$in': [1,3]])
...> %Mongo.Error{} = collection |> Mongo.Collection.count(a: ['$in': 1]) # $in should take a list, so this triggers an error
...> collection |> Mongo.Collection.count!(a: ['$in': 1])
** (Mongo.Bang) :"cmd error"
Source

Summary
↑

aggregate!(pipeline, collection)

See aggregate/2
aggregate(collection, pipeline)

Calculates aggregate values for the data in the collection (see db.collection.aggregate)
count!(collection)

See count/1
count!(collection, query)

See count/2
count!(collection, query, skip_limit)

See count/3
count(collection, query \\ %{}, skip_limit \\ %{})

Count documents in the collection
createIndex(collection, name, key, unique \\ false)

Creates an index for the collection
delete(collection, query, justOne \\ false)

Removes an existing document or documents in the collection (see db.collection.remove)
distinct!(key, collection)

See distinct/2
distinct!(key, query, collection)

See distinct/3
distinct(collection, key, query \\ %{})

Finds the distinct values for a specified field across a single collection (see db.collection.distinct)
drop!(collection)

See drop/1
drop(collection)

Drops the collection
find(collection, criteria \\ %{}, projection \\ %{})

Creates a %Mongo.Find{} for a given collection, query and projection
group!(key, collection)

See group/2
group!(key, reduce, collection)

See group/3
group!(key, reduce, initial, collection)

See group/4
group!(key, reduce, initial, params, collection)

See group/5
group(collection, key, reduce \\ "function(k, vs){return Array.sum(vs)}", initial \\ %{}, params \\ %{})

Groups documents in the collection by the specified key
insert!(docs, collection)

See insert/2
insert(docs, collection)

Insert a list of documents into the collection
insert_one!(doc, collection)

See insert_one/2
insert_one(doc, collection)

Insert one document into the collection returns the document it received
mr!(map, collection)

See mr/2
mr!(map, reduce, collection)

See mr/3
mr!(map, reduce, out, collection)

See mr/4
mr!(map, reduce, out, more, collection)

See mr/5
mr(collection, map, reduce \\ "function(k, vs){return Array.sum(vs)}", out \\ %{inline: true}, params \\ %{})

Provides a wrapper around the mapReduce command
new(db, name)

New collection
opts(collection, new_opts)

Adds options to the collection overwriting database options
read_opts(collection)

Gets read default options
update(collection, query, update, upsert \\ false, multi \\ false)

Modifies an existing document or documents in the collection
write_opts(collection)

Gets write default options

Functions

aggregate(collection, pipeline)
(function) # ↑

Calculates aggregate values for the data in the collection (see db.collection.aggregate)

iex> collection = Mongo.connect! |> Mongo.db("test") |> Mongo.Db.collection("anycoll")
...> collection |> Mongo.Collection.aggregate([
...>    %{'$skip': 1},
...>    %{'$limit': 5},
...>    %{'$project': %{'_id': false, value: true}} ])
[%{value: 1}, %{value: 1}, %{value: 1}, %{value: 1}, %{value: 3}]
Source
aggregate!(pipeline, collection)
(function) # ↑

See aggregate/2

Source
count(collection, query \\ %{}, skip_limit \\ %{})
(function) # ↑

Count documents in the collection

If query is not specify, it counts all document collection. skip_limit is a map that specify Mongodb otions skip and limit

Source
count!(collection)
(function) # ↑

See count/1

Source
count!(collection, query)
(function) # ↑

See count/2

Source
count!(collection, query, skip_limit)
(function) # ↑

See count/3

Source
createIndex(collection, name, key, unique \\ false)
(function) # ↑

Creates an index for the collection

Source
delete(collection, query, justOne \\ false)
(function) # ↑

Removes an existing document or documents in the collection (see db.collection.remove)

iex> collection = Mongo.connect! |> Mongo.db("test") |> Mongo.Db.collection("anycoll")
...> collection |> Mongo.Collection.delete(%{b: 789})
:ok
Source
distinct(collection, key, query \\ %{})
(function) # ↑

Finds the distinct values for a specified field across a single collection (see db.collection.distinct)

iex> collection = Mongo.connect! |> Mongo.db("test") |> Mongo.Db.collection("anycoll")
...> collection |> Mongo.Collection.distinct!("value", %{value: %{"$lt": 3}})
[0, 1]
Source
distinct!(key, collection)
(function) # ↑

See distinct/2

Source
distinct!(key, query, collection)
(function) # ↑

See distinct/3

Source
drop(collection)
(function) # ↑

Drops the collection

returns :ok or a string containing the error message

Source
drop!(collection)
(function) # ↑

See drop/1

Source
find(collection, criteria \\ %{}, projection \\ %{})
(function) # ↑

Creates a %Mongo.Find{} for a given collection, query and projection

See Mongo.Find for details.

Source
group(collection, key, reduce \\ "function(k, vs){return Array.sum(vs)}", initial \\ %{}, params \\ %{})
(function) # ↑

Groups documents in the collection by the specified key

iex> collection = Mongo.connect! |> Mongo.db("test") |> Mongo.Db.collection("anycoll")
...> collection |> Mongo.Collection.group!(%{a: true}) |> is_list
true

[%{a: 0.0}, %{a: 1.0}, %{a: 2.0}, ...]
Source
group!(key, collection)
(function) # ↑

See group/2

Source
group!(key, reduce, collection)
(function) # ↑

See group/3

Source
group!(key, reduce, initial, collection)
(function) # ↑

See group/4

Source
group!(key, reduce, initial, params, collection)
(function) # ↑

See group/5

Source
insert(docs, collection)
(function) # ↑

Insert a list of documents into the collection

iex> collection = Mongo.connect! |> Mongo.db("test") |> Mongo.Db.collection("anycoll")
...> [%{a: 23}, %{a: 24, b: 1}] |> Mongo.Collection.insert(collection) |> elem(1)
[%{a: 23}, %{a: 24, b: 1}]

You can chain it with Mongo.assign_id/1 when you need ids for further processing. If you don’t Mongodb will assign ids automatically.

iex> collection = Mongo.connect! |> Mongo.db("test") |> Mongo.Db.collection("anycoll")
...> [%{a: 23}, %{a: 24, b: 1}] |> Mongo.assign_id |> Mongo.Collection.insert(collection) |> elem(1) |> Enum.at(0) |> Map.has_key?(:"_id")
true

Mongo.Collection.insert returns the list of documents it received.

Source
insert!(docs, collection)
(function) # ↑

See insert/2

Source
insert_one(doc, collection)
(function) # ↑

Insert one document into the collection returns the document it received.

iex> collection = Mongo.connect! |> Mongo.db("test") |> Mongo.Db.collection("anycoll")
...> %{a: 23} |> Mongo.Collection.insert_one(collection) |> elem(1)
%{a: 23}
Source
insert_one!(doc, collection)
(function) # ↑

See insert_one/2

Source
mr(collection, map, reduce \\ "function(k, vs){return Array.sum(vs)}", out \\ %{inline: true}, params \\ %{})
(function) # ↑

Provides a wrapper around the mapReduce command

Returns :ok or an array of documents (with option :inline active - set by default).

iex> collection = Mongo.connect! |> Mongo.db("test") |> Mongo.Db.collection("anycoll")
...> Mongo.Collection.mr!(collection, "function(d){emit(this._id, this.value*2)}", "function(k, vs){return Array.sum(vs)}") |> is_list
true

%{_id: Bson.ObjectId.from_string("542aa3fab9742bc0d5eaa12d"), value: 0.0}

iex> collection = Mongo.connect! |> Mongo.db("test") |> Mongo.Db.collection("anycoll")
...> Mongo.Collection.mr!(collection, "function(d){emit('z', 3*this.value)}", "function(k, vs){return Array.sum(vs)}", "mrcoll")
:ok
Source
mr!(map, collection)
(function) # ↑

See mr/2

Source
mr!(map, reduce, collection)
(function) # ↑

See mr/3

Source
mr!(map, reduce, out, collection)
(function) # ↑

See mr/4

Source
mr!(map, reduce, out, more, collection)
(function) # ↑

See mr/5

Source
new(db, name)
(function) # ↑

New collection

Source
opts(collection, new_opts)
(function) # ↑

Adds options to the collection overwriting database options

new_opts must be a map with zero or more pairs represeting one of these options:

  • read: :awaitdata, :nocursortimeout, :slaveok, :tailablecursor
  • write concern: :wc
  • socket: :mode, :timeout
Source
read_opts(collection)
(function) # ↑

Gets read default options

Source
update(collection, query, update, upsert \\ false, multi \\ false)
(function) # ↑

Modifies an existing document or documents in the collection

iex> collection = Mongo.connect! |> Mongo.db("test") |> Mongo.Db.collection("anycoll")
...> collection |> Mongo.Collection.update(%{a: 456}, %{a: 123, b: 789})
:ok
Source
write_opts(collection)
(function) # ↑

Gets write default options

Source