|
DataMapper is an object-relational mapper library written in Ruby that follows the active record pattern even though the name implies it follows the data mapper pattern. While DataMapper 1 may not have achieved total decoupling between object and database suggested by the data mapper pattern, it appears DataMapper 2 intended to change this (''a la'' (Virtus ), a library adapted from DataMapper).〔(【引用サイトリンク】title=datamapper wiki: Roadmap )〕 The DataMapper 2 project was renamed before launch and was released as (Ruby Object Mapper (ROM) ) in August 2013.〔(【引用サイトリンク】title=Where is DataMapper 2? )〕 Some features of DataMapper:〔http://datamapper.org/why〕 * Eager loading of child associations to avoid (N+1) queries * Lazy loading of select properties, e.g., larger fields * Query chaining, and not evaluating the query until absolutely necessary (using a lazy array implementation) * An API not too heavily oriented to SQL databases DataMapper was designed to be a more abstract ORM, not strictly SQL, based on Martin Fowler's enterprise pattern. As a result, DataMapper adapters have been built for other non-SQL databases, such as CouchDB,〔http://github.com/kabari/dm-couchdb-adapter/tree/master〕 Apache Solr,〔http://github.com/lritter/dm-solr-adapter/tree/master〕 and webservices such as Salesforce.com.〔http://github.com/halorgium/dm-salesforce/tree/master〕 ==References== 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「DataMapper」の詳細全文を読む スポンサード リンク
|