class Mongo::Collection

• Mongo::Collection
• Reference
• Object

Overview

A Collection provides access to a MongoDB collection.

collection = client["database_name"]["collection_name"]

Included Modules

• Mongo::WithReadConcern
• Mongo::WithReadPreference
• Mongo::WithWriteConcern

Defined in:

Instance Method Summary

• #aggregate(pipeline : Array, *, allow_disk_use : Bool | Nil = nil, batch_size : Int32 | Nil = nil, max_time_ms : Int64 | Nil = nil, bypass_document_validation : Bool | Nil = nil, collation : Collation | Nil = nil, hint : String | H | Nil = nil, comment : String | Nil = nil, read_concern : ReadConcern | Nil = nil, write_concern : WriteConcern | Nil = nil, read_preference : ReadPreference | Nil = nil, session : Session::ClientSession | Nil = nil) : Mongo::Cursor | Nil forall H

  Runs an aggregation framework pipeline.

• #bulk(ordered : Bool = true, session : Session::ClientSession | Nil = nil)

  Create a Mongo::Bulk instance.

• #bulk_write(requests : Array(Bulk::WriteModel), *, ordered : Bool, bypass_document_validation : Bool | Nil = nil, session : Session::ClientSession | Nil = nil) : Bulk::WriteResult

  Executes multiple write operations.

• #command(operation, write_concern : WriteConcern | Nil = nil, read_concern : ReadConcern | Nil = nil, read_preference : ReadPreference | Nil = nil, session : Session::ClientSession | Nil = nil, **args, &)

  Execute a command on the server targeting the collection.

• #command(operation, write_concern : WriteConcern | Nil = nil, read_concern : ReadConcern | Nil = nil, read_preference : ReadPreference | Nil = nil, session : Session::ClientSession | Nil = nil, **args)

  Execute a command on the server targeting the collection.

• #count_documents(filter = BSON.new, *, skip : Int32 | Nil = nil, limit : Int32 | Nil = nil, collation : Collation | Nil = nil, hint : String | H | Nil = nil, max_time_ms : Int64 | Nil = nil, read_preference : ReadPreference | Nil = nil, session : Session::ClientSession | Nil = nil) : Int32 forall H

  Count the number of documents in a collection that match the given filter.

• #create_index(keys, *, options = NamedTuple.new, commit_quorum : Int32 | String | Nil = nil, max_time_ms : Int64 | Nil = nil, write_concern : WriteConcern | Nil = nil, session : Session::ClientSession | Nil = nil) : Commands::CreateIndexes::Result | Nil

  This is a convenience method for creating a single index.

• #create_indexes(models : Array, *, commit_quorum : Int32 | String | Nil = nil, max_time_ms : Int64 | Nil = nil, write_concern : WriteConcern | Nil = nil, session : Session::ClientSession | Nil = nil) : Commands::CreateIndexes::Result | Nil

  Creates multiple indexes in the collection.

• #database : Mongo::Database

  The parent database.

• #delete_many(filter, *, collation : Collation | Nil = nil, hint : String | H | Nil = nil, ordered : Bool | Nil = nil, write_concern : WriteConcern | Nil = nil, session : Session::ClientSession | Nil = nil) : Commands::Common::DeleteResult | Nil forall H

  Deletes multiple documents.

• #delete_one(filter, *, collation : Collation | Nil = nil, hint : String | H | Nil = nil, ordered : Bool | Nil = nil, write_concern : WriteConcern | Nil = nil, session : Session::ClientSession | Nil = nil) : Commands::Common::DeleteResult | Nil forall H

  Deletes one document.

• #distinct(key : String, *, filter = nil, read_concern : ReadConcern | Nil = nil, collation : Collation | Nil = nil, read_preference : ReadPreference | Nil = nil, session : Session::ClientSession | Nil = nil) : Array

  Finds the distinct values for a specified field across a single collection.

• #drop_index(name : String, *, max_time_ms : Int64 | Nil = nil, write_concern : WriteConcern | Nil = nil, session : Session::ClientSession | Nil = nil) : Commands::Common::BaseResult | Nil

  Drops a single index from the collection by the index name.

• #drop_indexes(*, max_time_ms : Int64 | Nil = nil, write_concern : WriteConcern | Nil = nil, session : Session::ClientSession | Nil = nil) : Commands::Common::BaseResult | Nil

  Drops all indexes in the collection.

• #estimated_document_count(*, max_time_ms : Int64 | Nil = nil, read_preference : ReadPreference | Nil = nil, session : Session::ClientSession | Nil = nil) : Int32

  Gets an estimate of the count of documents in a collection using collection metadata.

• #find(filter = BSON.new, *, sort = nil, projection = nil, hint : String | H | Nil = nil, skip : Int32 | Nil = nil, limit : Int32 | Nil = nil, batch_size : Int32 | Nil = nil, single_batch : Bool | Nil = nil, comment : String | Nil = nil, max_time_ms : Int64 | Nil = nil, read_concern : ReadConcern | Nil = nil, max = nil, min = nil, return_key : Bool | Nil = nil, show_record_id : Bool | Nil = nil, tailable : Bool | Nil = nil, oplog_replay : Bool | Nil = nil, no_cursor_timeout : Bool | Nil = nil, await_data : Bool | Nil = nil, allow_partial_results : Bool | Nil = nil, allow_disk_use : Bool | Nil = nil, collation : Collation | Nil = nil, read_preference : ReadPreference | Nil = nil, session : Session::ClientSession | Nil = nil) : Mongo::Cursor forall H

  Finds the documents matching the model.

• #find_one(filter = BSON.new, *, sort = nil, projection = nil, hint : String | H | Nil = nil, skip : Int32 | Nil = nil, comment : String | Nil = nil, max_time_ms : Int64 | Nil = nil, read_concern : ReadConcern | Nil = nil, max = nil, min = nil, return_key : Bool | Nil = nil, show_record_id : Bool | Nil = nil, oplog_replay : Bool | Nil = nil, no_cursor_timeout : Bool | Nil = nil, allow_partial_results : Bool | Nil = nil, collation : Collation | Nil = nil, read_preference : ReadPreference | Nil = nil, session : Session::ClientSession | Nil = nil) : BSON | Nil forall H

  Finds the document matching the model.

• #find_one_and_delete(filter, *, sort = nil, fields = nil, bypass_document_validation : Bool | Nil = nil, write_concern : WriteConcern | Nil = nil, collation : Collation | Nil = nil, hint : String | H | Nil = nil, max_time_ms : Int64 | Nil = nil, session : Session::ClientSession | Nil = nil) : BSON | Nil forall H

  Finds a single document and deletes it, returning the original.

• #find_one_and_replace(filter, replacement, *, sort = nil, new : Bool | Nil = nil, fields = nil, upsert : Bool | Nil = nil, bypass_document_validation : Bool | Nil = nil, write_concern : WriteConcern | Nil = nil, collation : Collation | Nil = nil, array_filters = nil, hint : String | H | Nil = nil, max_time_ms : Int64 | Nil = nil, session : Session::ClientSession | Nil = nil) : BSON | Nil forall H

  Finds a single document and replaces it, returning either the original or the replaced document.

• #find_one_and_update(filter, update, *, sort = nil, new : Bool | Nil = nil, fields = nil, upsert : Bool | Nil = nil, bypass_document_validation : Bool | Nil = nil, write_concern : WriteConcern | Nil = nil, collation : Collation | Nil = nil, array_filters = nil, hint : String | H | Nil = nil, max_time_ms : Int64 | Nil = nil, session : Session::ClientSession | Nil = nil) : BSON | Nil forall H

  Finds a single document and updates it, returning either the original or the updated document.

• #insert_many(documents : Array, *, ordered : Bool | Nil = nil, write_concern : WriteConcern | Nil = nil, bypass_document_validation : Bool | Nil = nil, session : Session::ClientSession | Nil = nil) : Commands::Common::InsertResult | Nil

  Inserts the provided document.

• #insert_one(document, *, write_concern : WriteConcern | Nil = nil, bypass_document_validation : Bool | Nil = nil, session : Session::ClientSession | Nil = nil) : Commands::Common::InsertResult | Nil

  Inserts the provided document.

• #list_indexes(session : Session::ClientSession | Nil = nil) : Mongo::Cursor | Nil

  Gets index information for all indexes in the collection.

• #name : CollectionKey

  The collection name.

• #read_concern : ReadConcern | Nil

  Read concern accessor.

• #read_concern=(read_concern : ReadConcern | Nil)

  Read concern accessor.

• #read_preference : ReadPreference | Nil

  ReadPreference accessor.

• #read_preference=(read_preference : ReadPreference | Nil)

  ReadPreference accessor.

• #replace_one(filter, replacement, *, upsert : Bool = false, collation : Collation | Nil = nil, hint : String | H | Nil = nil, ordered : Bool | Nil = nil, write_concern : WriteConcern | Nil = nil, bypass_document_validation : Bool | Nil = nil, session : Session::ClientSession | Nil = nil) : Commands::Common::UpdateResult | Nil forall H

  Replaces a single document.

• #stats(*, scale : Int32 | Nil = nil, session : Session::ClientSession | Nil = nil) : BSON | Nil

  Returns a variety of storage statistics for the collection.

• #update_many(filter, update, *, upsert : Bool = false, array_filters = nil, collation : Collation | Nil = nil, hint : String | H | Nil = nil, ordered : Bool | Nil = nil, write_concern : WriteConcern | Nil = nil, bypass_document_validation : Bool | Nil = nil, session : Session::ClientSession | Nil = nil) : Commands::Common::UpdateResult | Nil forall H

  Updates multiple documents.

• #update_one(filter, update, *, upsert : Bool = false, array_filters = nil, collation : Collation | Nil = nil, hint : String | H | Nil = nil, ordered : Bool | Nil = nil, write_concern : WriteConcern | Nil = nil, bypass_document_validation : Bool | Nil = nil, session : Session::ClientSession | Nil = nil) : Commands::Common::UpdateResult | Nil forall H

  Updates one document.

• #watch(pipeline : Array = [] of BSON, *, full_document : String | Nil = nil, start_at_operation_time : Time | Nil = nil, resume_after : BSON | Nil = nil, start_after : BSON | Nil = nil, max_await_time_ms : Int64 | Nil = nil, batch_size : Int32 | Nil = nil, collation : Collation | Nil = nil, read_concern : ReadConcern | Nil = nil, read_preference : ReadPreference | Nil = nil, session : Session::ClientSession | Nil = nil) : Mongo::ChangeStream::Cursor

  Returns a ChangeStream::Cursor watching a specific collection.

• #with_session(**args, &)

  Initialize a session that has the same lifetime as the block.

• #write_concern : WriteConcern | Nil

  Write concern accessor.

• #write_concern=(write_concern : WriteConcern | Nil)

  Write concern accessor.

Instance Method Detail

client = Mongo::Client.new
collection = client["db"]["coll"]

spawn {
  cursor = collection.watch(
    [
      {"$match": {"operationType": "insert"}},
    ],
    max_await_time_ms: 10000
  )
  # cursor.of(BSON) converts to the Mongo::ChangeStream::Document(BSON) type.
  cursor.of(BSON).each { |doc|
    puts doc.to_bson.to_json
  }
}

100.times do |i|
  collection.insert_one({count: i})
end

sleep

client = Mongo::Client.new
collection = client["db"]["coll"]

collection.with_session(causal_consistency: true) do |collection, session|
  5.times { |idx|
    # No need to provide: `session: session`.
    collection.insert_one({number: idx})
    collection.find_one({number: idx})
  }
end