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).[1] The DataMapper 2 project was renamed before launch and was released as Ruby Object Mapper (ROM) in August 2013.[2]
Some features of DataMapper:[3]
- 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.[4] As a result, DataMapper adapters have been built for other non-SQL databases, such as CouchDB,[5] Apache Solr,[6] and webservices such as Salesforce.com.[7]
References
edit- ^ "datamapper wiki: Roadmap". GitHub.
- ^ "Where is DataMapper 2?". Google Groups.
- ^ "DataMapper - Why DataMapper?". Archived from the original on 2010-10-08. Retrieved 2010-10-12.
- ^ Fowler, Martin; David Rice; Matthew Foemmel; Edward Hieatt; Robert Mee; Randy Stafford (November 2002). Patterns of Enterprise Application Architecture. Addison-Wesley. ISBN 0-321-12742-0.
- ^ "Kabari's dm-couchdb-adapter at master - GitHub". GitHub. Archived from the original on 2009-08-27. Retrieved 2016-01-02.
- ^ "Lritter/Dm-solr-adapter". GitHub. 13 August 2019.
- ^ "Dm-salesforce". GitHub. 22 February 2020.
External links
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