Class: Lotus::Model::Adapters::SqlAdapter Private

Inherits:
Abstract
  • Object
show all
Includes:
Implementation
Defined in:
lib/lotus/model/adapters/sql_adapter.rb

Overview

This class is part of a private API. You should avoid using this class if possible, as it may be removed or be changed in the future.

Adapter for SQL databases

In order to use it with a specific database, you must require the Ruby gem before of loading Lotus::Model.

See Also:

Since:

  • 0.1.0

Instance Method Summary collapse

Methods included from Implementation

#all, #find, #first, #last, #persist

Methods inherited from Abstract

#all, #find, #first, #last, #persist

Constructor Details

#initialize(mapper, uri) ⇒ Lotus::Model::Adapters::SqlAdapter

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Initialize the adapter.

Lotus::Model uses Sequel. For a complete reference of the connection URI, please see: sequel.jeremyevans.net/rdoc/files/doc/opening_databases_rdoc.html

Parameters:

  • mapper (Object) —

    the database mapper

  • uri (String) —

    the connection uri for the database

Raises:

See Also:

Since:

  • 0.1.0



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# File 'lib/lotus/model/adapters/sql_adapter.rb', line 44

def initialize(mapper, uri)
  super
  @connection = Sequel.connect(@uri)
rescue Sequel::AdapterNotFound => e
  raise DatabaseAdapterNotFound.new(e.message)
end

Instance Method Details

#clear(collection) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Deletes all the records from the given collection.

Parameters:

  • collection (Symbol) —

    the target collection (it must be mapped).

Since:

  • 0.1.0



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# File 'lib/lotus/model/adapters/sql_adapter.rb', line 101

def clear(collection)
  command(query(collection)).clear
end

#command(query) ⇒ Lotus::Model::Adapters::Sql::Command

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Fabricates a command for the given query.

Parameters:

Returns:

See Also:

Since:

  • 0.1.0



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# File 'lib/lotus/model/adapters/sql_adapter.rb', line 116

def command(query)
  Sql::Command.new(query)
end

#connection_string ⇒ String

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns a string which can be executed to start a console suitable for the configured database, adding the necessary CLI flags, such as url, password, port number etc.

Returns:

  • (String)

Since:

  • 0.3.0



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# File 'lib/lotus/model/adapters/sql_adapter.rb', line 226

def connection_string
  Sql::Console.new(@uri).connection_string
end

#create(collection, entity) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Creates a record in the database for the given entity. It assigns the ‘id` attribute, in case of success.

Parameters:

  • collection (Symbol) —

    the target collection (it must be mapped).

  • entity (#id=) —

    the entity to create

Returns:

  • (Object) —

    the entity

Since:

  • 0.1.0



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# File 'lib/lotus/model/adapters/sql_adapter.rb', line 61

def create(collection, entity)
  command(
    query(collection)
  ).create(entity)
end

#delete(collection, entity) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Deletes a record in the database corresponding to the given entity.

Parameters:

  • collection (Symbol) —

    the target collection (it must be mapped).

  • entity (#id) —

    the entity to delete

Since:

  • 0.1.0



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# File 'lib/lotus/model/adapters/sql_adapter.rb', line 89

def delete(collection, entity)
  command(
    _find(collection, entity.id)
  ).delete
end

#execute(raw) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Executes raw sql directly on the connection

Parameters:

  • raw (String) —

    the raw sql statement to execute on the connection

Returns:

  • (Object)

Raises:

Since:

  • 0.3.1



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# File 'lib/lotus/model/adapters/sql_adapter.rb', line 239

def execute(raw)
  begin
    @connection.execute(raw)
  rescue Sequel::DatabaseError => e
    raise Lotus::Model::InvalidQueryError.new(e.message)
  end
end

#query(collection, context = nil, &blk) ⇒ Lotus::Model::Adapters::Sql::Query

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Fabricates a query

Parameters:

  • collection (Symbol) —

    the target collection (it must be mapped).

  • blk (Proc) —

    a block of code to be executed in the context of the query.

Returns:

See Also:

Since:

  • 0.1.0



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# File 'lib/lotus/model/adapters/sql_adapter.rb', line 132

def query(collection, context = nil, &blk)
  Sql::Query.new(_collection(collection), context, &blk)
end

#transaction(options = {}) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Wraps the given block in a transaction.

For performance reasons the block isn’t in the signature of the method, but it’s yielded at the lower level.

Examples:

Basic usage

require 'lotus/model'

class Article
  include Lotus::Entity
  attributes :title, :body
end

class ArticleRepository
  include Lotus::Repository
end

article = Article.new(title: 'Introducing transactions',
  body: 'lorem ipsum')

ArticleRepository.transaction do
  ArticleRepository.dangerous_operation!(article) # => RuntimeError
  # !!! ROLLBACK !!!
end

Policy rollback always

require 'lotus/model'

class Article
  include Lotus::Entity
  attributes :title, :body
end

class ArticleRepository
  include Lotus::Repository
end

article = Article.new(title: 'Introducing transactions',
  body: 'lorem ipsum')

ArticleRepository.transaction(rollback: :always) do
  ArticleRepository.create(article)
  # !!! ROLLBACK !!!
end

# The operation is rolled back, even in no exceptions were raised.

Policy rollback reraise

require 'lotus/model'

class Article
  include Lotus::Entity
  attributes :title, :body
end

class ArticleRepository
  include Lotus::Repository
end

article = Article.new(title: 'Introducing transactions',
  body: 'lorem ipsum')

ArticleRepository.transaction(rollback: :reraise) do
  ArticleRepository.dangerous_operation!(article) # => RuntimeError
  # !!! ROLLBACK !!!
end # => RuntimeError

# The operation is rolled back, but RuntimeError is re-raised.

Parameters:

  • options (Hash) (defaults to: {}) —

    options for transaction

  • rollback (Hash) —

    a customizable set of options

See Also:

Since:

  • 0.2.3



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# File 'lib/lotus/model/adapters/sql_adapter.rb', line 213

def transaction(options = {})
  @connection.transaction(options) do
    yield
  end
end

#update(collection, entity) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Updates a record in the database corresponding to the given entity.

Parameters:

  • collection (Symbol) —

    the target collection (it must be mapped).

  • entity (#id) —

    the entity to update

Returns:

  • (Object) —

    the entity

Since:

  • 0.1.0



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# File 'lib/lotus/model/adapters/sql_adapter.rb', line 76

def update(collection, entity)
  command(
    _find(collection, entity.id)
  ).update(entity)
end