Lesson plan
DataMapper
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). The DataMapper 2 project was renamed before launch and was released as Ruby Object Mapper (ROM) in August 2013. Some features of DataMapper: * 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, Apache Solr, and webservices such as Salesforce.com.
Article summary
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). The DataMapper 2 project was renamed before launch and was released as Ruby Object Mapper (ROM) in August 2013. Some features of DataMapper: * 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, Apache Solr, and webservices such as Salesforce.com.
Key claims
- release date: 2013 — source: Wikipedia · confidence 0.95
Discussion questions
- Summarise the article in your own words. Which single claim would you verify first, and why?
- The record states that the release date is "2013". What evidence would count against this claim?
- Which claim in this article is most likely to be revised as the sources update? How would you check its current status?
- If two sources disagreed about one of these facts, what would you need in order to trust one over the other?
Bibliography
- Wikipedia https://en.wikipedia.org/w/index.php?oldid=1326617170
Key claims and bibliography are generated from the same tracked claims and sources as the article page.