[Introduction]
during IToo project will know when something a little EF, and later when learning ssh mall contacted hibernate, although in fact A .NET environment, the other in the java environment, but the basic principles are the It is about the same! It is a kind of ORM framework!
SUMMARY []
object-relational ORM (object relation mapping) mapping relationship between the conversion object-oriented and object-relational data model. Based on the data stored in a relational database, data access interface a virtual object-oriented. Ideally, based on such an object-oriented interface a, oo a persistent object should not need to know any data stored in the relational database implementation details.
[Form] ORM framework
1.EF (Entity framework) Entity Framework: ado.net support the development of a set of technical data-oriented software applications. Microsoft is an ORM framework
In fact, in the figure above we can see the use of ORM framework, use is mandatory, not prone to error, implemented directly by the operating entity table to table, and no use of ORM framework, we need to access the database driver layer , ADO.NET operation data, the operation is a weak type, is prone to error. In fact, the underlying code is ORM framework of ADO.NET, but the code is a good package, the user can be used directly, very convenient!
2.linq to sql
In fact, in addition to EF ORM framework for mapping, as well as linq to sql, noticed this one is because the creation vs EF mapping in the following also called linq to sql, in fact, this is also an ORM framework just apply some lightweight, small ORM applicable; interested can try! Related visit Bowen: HTTP: //www.cnblogs.com/yukaizhao/archive/2010/05/13/linq_to_sql_1.html
3.CYQ.Data automated programming framework of
this framework is actually in principle on the basis of EF formed through adaptation one kind ORM framework, details see:
http://www.cnblogs.com/cyq1162/p/5634414.html
4. NHibernate
NHibernate is an object-oriented environment .NET / relational mapping tool. Object / relational mapping (object / relational mapping, ORM) this term means a technique for mapping the object model representation of the object to SQL-based relational model of data structure to. So NHibernate with the Entity
Framework is very similar.
In fact, knock ssh mall when I have been met a noun: data persistence, time has not quite understand in the end what it meant, and later in the study, it was found that a foundation: data persistence (PO) is to memory stored data model to model, and converting the data model stored in the model memory collectively data model may be any data structure or object model storage model may be a relational model, XML, binary streams. cmp and Hibernate but the object model to achieve the conversion between different relational model.