# ANN: Sequel 1.5.0 Released **URL:** \ **Category:** Ruby\ **Created:** [April 29, 2008, 7:40pm UTC](https://www.ruby-forum.com/t/ann-sequel-1-5-0-released/136201 "2008-04-29T19:40:46Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![nerdmaster](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/c68b51/32.png) [@nerdmaster](https://www.ruby-forum.com/u/nerdmaster)\ **Post date:** [April 29, 2008, 7:40pm UTC](https://www.ruby-forum.com/t/ann-sequel-1-5-0-released/136201/1 "2008-04-29T19:40:46Z")
Sequel is a lightweight database access toolkit for Ruby. - Sequel provides thread safety, connection pooling and a concise DSL for constructing database queries and table schemas. - Sequel also includes a lightweight but comprehensive ORM layer for mapping records to Ruby objects and handling associated records. - Sequel makes it easy to deal with multiple records without having to break your teeth on SQL. - Sequel currently has adapters for ADO, DB2, DBI, Informix, JDBC, MySQL, ODBC, OpenBase, Oracle, PostgreSQL and SQLite3. Sequel 1.5.0 has been released and should be available on the gem mirrors. 1.5.0 has the following exciting new features: You can now graph a dataset and have the result split into component tables: DB[:artists].graph(:albums, :artist\_id=\>:id).first # =\> {:artists=\>{:id=\>artists.id, :name=\>artists.name}, \ # :albums=\>{:id=\>albums.id, :name=\>albums.name, :artist\_id=\>albums.artist\_id}} This aliases columns if necessary so they don’t stomp on each other, which is what usually happens if you just join the tables: DB[:artists].left\_outer\_join(:albums, :artist\_id=\>:id).first # =\> {:id=\>(albums.id||artists.id), :name=\>(albums.name||artist.names), :artist\_id=\>albums.artist\_id} Models can use graph as well, in which case the values will be model objects: Artist.graph(Album, :artist\_id=\>:id) # =\> {:artists=\>#\, :albums=\>#\} Models can now eager load via .eager\_graph, which will load all the results and all associations in a single query. This is necessary if you want to filter on columns in associated tables. It works exactly the same way as .eager, and supports cascading of associations as well: # Artist.one\_to\_many :albums # Album.one\_to\_many :tracks # Track.many\_to\_one :genre Artist.eager\_graph(:albums=\>{:tracks=\>:genre}).filter( :tracks\_name=\>“Firewire”).all This will give you all artists have have an album with a track named “Firewire”, and calling .albums on one of those artists will only return albums that have a track named “Firewire”, and calling .tracks on one of those albums will return only the track(s) named “Firewire”. You can use set\_graph\_aliases to select specific columns: DB[:artists].graph(:albums, :artist\_id=\>:id).set\_graph\_aliases( :artist\_name=\>[:artists, :name], :album\_name=\>[:albums, :name]).first # =\> {:artists=\>{:name=\>artists.name}, :albums=\>{:name=\>albums.name}} You can use eager\_graph with set\_graph\_aliases to have eager loading with control over the SELECT clause. All associations now update their reciprocal associations whenever the association methods are used, so you don’t need to refresh the association or model to have the reciprocal association updated: Album.many\_to\_one :band Band.one\_to\_many :albums # Note that all of these associations are cached, # so after the first access there are no additional # database queries to fetch associated records. # many\_to\_one setter adds to reciprocal association band1.albums # =\> [] album1.band = band1 band1.albums # =\> [album1] band2.albums # =\> [] album1.band = band2 band1.albums # =\> [] band2.albums # =\> [album1] album1.band = band2 band2.albums # =\> [album1] album1.band = nil band2.albums # =\> [] # one\_to\_many add\_\* method sets reciprocal association # one\_to\_many remove\_\* method removes reciprocal association album1.band # =\> nil band1.add\_album(album1) album1.band # =\> band1 band2.add\_album(album1) album1.band # =\> band2 band2.remove\_album(album1) album1.band # =\> nil Post.many\_to\_many :tags Tag.many\_to\_many :posts # many\_to\_many add\_\* method adds to reciprocal association # many\_to\_many remove\_\* method removes from reciprocal association post1.tags # =\> [] tag1.posts # =\> [] tag1.add\_post(post1) post1.tags # =\> [tag1] tag1.posts # =\> [post1] tag1.remove\_post(post1) post1.tags # =\> [] tag1.posts # =\> [] post1.add\_tag(tag1) post1.tags # =\> [tag1] tag1.posts # =\> [post1] post1.remove\_tag(tag1) post1.tags # =\> [] tag1.posts # =\> [] The MySQL and PostgreSQL adapters now support index types: index :some\_column, :type =\> :hash # or :spatial, :full\_text, :rtree, etc. Starting in Sequel 1.5.0, some methods are deprecated. These methods will be removed in Sequel 2.0.0. The deprecation framework is fairly flexible. You can choose where the messages get sent: Sequel::Deprecation.deprecation\_message\_stream = STDERR # the default Sequel::Deprecation.deprecation\_message\_stream = File.new(‘deprecation.txt’, ‘wb’) # A file Sequel::Deprecation.deprecation\_message\_stream = nil # ignore the messages You can even have all deprecation messages accompanied by a traceback, so you can see exactly where in your code you are using a deprecated method: Sequel::Deprecation.print\_tracebacks = true All deprecation methods come with an message telling you what alternative code will work. In addition to deprecating some methods, we removed the ability to have arrays returned instead of hashes. The array code still had debugging messages left it in, and we are not aware of anyone using it. Hashes have been returned by default since Sequel 0.3. We have also removed the Numeric date/time extensions (e.g. 3.days.ago). The existing extensions were incomplete, better ones are provided elsewhere, and the extensions were not really related to Sequel’s purpose. Sequel no longer depends on ParseTree, RubyInline, or ruby2ruby. They are still required to use the block filters. Sequel’s only gem dependency is on the tiny metaid. Sequel 1.5.0 has fixes for 12 tracker issues, including fixes to the Informix, MySQL, ODBC, ADO, JDBC, Postgres, and SQLite adapters. If you have any questions, please post on the Google Group. Thanks, Jeremy - {Project page}[[Google Code Archive - Long-term storage for Google Code Project Hosting.](http://code.google.com/p/ruby-sequel/)] - {Source code}[[GitHub - jeremyevans/sequel: Sequel: The Database Toolkit for Ruby](http://github.com/jeremyevans/sequel)] - {Bug tracking}[[Google Code Archive - Long-term storage for Google Code Project Hosting.](http://code.google.com/p/ruby-sequel/issues/list)] - {Google group}[[http://groups.google.com/group/sequel-talk](http://groups.google.com/group/sequel-talk)] - {RubyForge page}[[http://rubyforge.org/projects/sequel/](http://rubyforge.org/projects/sequel/)] - {API RDoc}[[http://sequel.rubyforge.org](http://sequel.rubyforge.org)]