Class: Ki::Orm::Db

Inherits:
Object show all
Includes:
Singleton
Defined in:
lib/ki/orm.rb

Overview

This singleton class establishes the database connection and CRUD operations.

Connecting

Db.instance.establish_connection

Queries

db = Db.instance
db.find 'users', {}
db.find 'users', { name: 'Homer' }

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#config ⇒ Object (readonly)

Returns the value of attribute config.



23
24
25
 
# File 'lib/ki/orm.rb', line 23

def config
  @config
end

#connection ⇒ Object (readonly)

Returns the value of attribute connection.



23
24
25
 
# File 'lib/ki/orm.rb', line 23

def connection
  @connection
end

#db ⇒ Object (readonly)

Returns the value of attribute db.



23
24
25
 
# File 'lib/ki/orm.rb', line 23

def db
  @db
end

Instance Method Details

#collection_names ⇒ Object

Returns

An array of all the collection names in the database.



60
61
62
 
# File 'lib/ki/orm.rb', line 60

def collection_names
  @db.collection_names.delete_if { |name| name =~ /^system/ }
end

#connection_string ⇒ Object 



47
48
49
50
51
52
53
54
 
# File 'lib/ki/orm.rb', line 47

def connection_string
  db = KiConfig.instance.database
  if ENV['MONGODB_URI']
    ENV['MONGODB_URI']
  else
    "#{db['host']}:#{db['port']}/#{db['name']}"
  end
end

#count(name, hash = {}) ⇒ Object

Count the number of hashes found in a specified collection, filtered by a hash attribute

Attributes

  • name - the mongo collection name

Options

  • hash - used for filtering

Returns

The number of objects found.

Examples

db = Db.instance
db.count 'users'
db.count 'users', { name: 'Homer' }



196
197
198
 
# File 'lib/ki/orm.rb', line 196

def count(name, hash = {})
  @db[name].count hash
end

#delete(name, hash) ⇒ Object

Deletes a hash from the database

Attributes

  • name - the mongo collection name

  • :hash - Filter by specific hash attributes. id required

Returns

Empty hash

Examples

db = Db.instance
db.delete 'users', { id: 'id' }
db.delete 'users', {}



167
168
169
170
171
172
173
 
# File 'lib/ki/orm.rb', line 167

def delete(name, hash)
  hash = nourish_hash_id hash
  r = @db[name].delete_many hash
  {
    deleted_item_count: r.documents[0]['n']
  }
end

#establish_connection ⇒ Object

Creates the mongo connection.

It first checks if the env variable “MONGODB_URI” is set. The required format: docs.mongodb.org/manual/reference/connection-string/

If the env variable is not set, it will use the information stored in config.yml.



33
34
35
36
37
38
39
40
41
42
43
44
45
 
# File 'lib/ki/orm.rb', line 33

def establish_connection
  Mongo::Logger.logger.level = Logger::FATAL
  # Mongo::Logger.logger       = Logger.new('mongo.log')
  # Mongo::Logger.logger.level = Logger::INFO

  @config = KiConfig.instance.database
  @db = if ENV['MONGODB_URI']
          Mongo::Client.new
        else
          Mongo::Client.new('mongodb://' + connection_string)
        end
  self
end

#find(name, hash = {}) ⇒ Object

Find a hash in the database

Attributes

  • name - the mongo collection name

Options

  • :hash - Filter by specific hash attributes

Returns

An array of hashes which match the query criteria

Examples

db = Db.instance
db.find 'users'
db.find 'users', { id: 'id' }
db.find 'users', { name: 'Homer' }



109
110
111
112
113
114
115
116
117
118
119
 
# File 'lib/ki/orm.rb', line 109

def find(name, hash = {})
  hash = nourish_hash_id hash
  a = nourish_hash_limit hash
  hash = a[0]
  limit = a[1]
  a = nourish_hash_sort hash
  hash = a[0]
  sort = a[1]

  @db[name].find(hash, limit).sort(sort).to_a.stringify_ids
end

#insert(name, hash) ⇒ Object

Insert a hash in the database.

Attributes

  • name - the mongo collection name

  • hash - the hash which will be inserted

Returns

The inserted hash.

  • :conditions - An SQL fragment like “administrator = 1”

Examples

db = Db.instance
db.insert 'users', { name: 'Homer' }



82
83
84
85
86
 
# File 'lib/ki/orm.rb', line 82

def insert(name, hash)
  item = @db[name].insert_one(hash)
  hash['id'] = item.inserted_id.to_s
  hash
end

#update(name, hash) ⇒ Object

Update a hash from the database

The method will update the hash obj with the id specified in the hash attribute.

Attributes

  • name - the mongo collection name

  • hash - requires at least the id of the hash which needs to be

    updated

Returns

The updated hash

Examples

db = Db.instance
db.update('users', { id: 'id', name: 'Sir Homer' })



141
142
143
144
145
146
147
148
 
# File 'lib/ki/orm.rb', line 141

def update(name, hash)
  hash = nourish_hash_id hash
  id = hash['_id'].to_s
  hash.delete('_id')
  @db[name].update_one({ '_id' => BSON::ObjectId(id) }, hash)
  hash['id'] = id
  hash
end