ConfORM概述
在ConfORM实战(1):概览中,描述了ConfORM简单使用。在ConfORM实战(2):原理中介绍了ConfORM的基本实现原理。如果你不熟悉ConfORM请查看前几篇文章,你也可以到http://code.google.com/p/codeconform/获取ConfORM。
在这之前,我们需要为HbmMapping写AsString()扩展方法:用于输出HbmMapping对象的Mapping,用于学习测试使用,具体代码参考这里。
在Domain设计中,关联关系有单向关联和双向关联两种,那么一对一我们可以分为单向一对一关联(Unidirectional one-to-one)、双向一对一主键关联(Bidirectional one-to-one (primary key association))、双向一对一外键关联(Bidirectional one-to-one (foreign key association))三种情况。这篇使用ConfORM“映射”这些Domain实例吧。
One-to-One语义
我们使用ObjectRelationalMapper类中的OneToOne方法定义两个对象一对一关系。
单向一对一关联(Unidirectional one-to-one)
1.Domain
设计单向一对一关联Domain实例,Person对象和Address对象,人有一个地址。
public class Person{public int Id { get; set; }public string Name { get; set; }public Address Address { get; set; }} public class Address{public int Id { get; set; }public string Street { get; set; }public int CivicNumber { get; set; }}
2.ConfORM
使用ConfORM来配置Domain,使之编译生成我们需要的HbmMapping对象。(注意黑体)
[Test]public void UnidirectionalOneToOneMappingDemo(){//show how work with one-to-one and how ConfORM understands OOPvar orm = new ObjectRelationalMapper();var mapper = new Mapper(orm);var entities = new[] { typeof(Person), typeof(Address) };//use the definition of table-to-class strategy class by classorm.TablePerClass(entities);// Defining relationsorm.OneToOne<Person, Address>();// Show the mapping to the consolevar mapping = mapper.CompileMappingFor(entities);Console.Write(mapping.AsString());}
3.Mapping
上面测试输出HbmMapping的映射字符串,如果你使用ReSharper或者TestDriven.Net工具测试,你可以看见下面输出:
对于单向一对一关联,实际就是设置IManyToOneMapper,ConfORM会在IPatternsAppliersHolder的ManyToOne和ManyToOnePath集合中匹配对应模式适配器,即匹配UnidirectionalOneToOneUniqueCascadeApplier模式适配器,进行相应操作。
UnidirectionalOneToOneUniqueCascadeApplier:应用IManyToOneMapper.Unique(true)和ManyToOneMapper.Cascade(applyCascade.HasValue?applyCascade.Value : Cascade.All)。
双向一对一主键关联(Bidirectional one-to-one (primary key association))
1.Domain
设计双向一对一关联Domain实例,Person对象和Address对象,人有一个地址,地址有一个人。
public class Person{public int Id { get; set; }public string Name { get; set; }public Address Address { get; set; }} public class Address{public int Id { get; set; }public Person Person { get; set; }public string Street { get; set; }public int CivicNumber { get; set; }}
2.ConfORM
使用ConfORM来配置Domain,使之编译生成我们需要的HbmMapping对象。其实这个代码和上面的一样:
[Test]public void BidirectionalOneToOneMappingDemo1(){//show how work with one-to-one and how ConfORM understands OOPvar orm = new ObjectRelationalMapper();var mapper = new Mapper(orm);var entities = new[] { typeof(Person), typeof(Address) };//use the definition of table-to-class strategy class by classorm.TablePerClass(entities);// Defining relationsorm.OneToOne<Person, Address>();//or orm.OneToOne<Address,Person>(); // Show the mapping to the consolevar mapping = mapper.CompileMappingFor(entities);Console.Write(mapping.AsString());}
3.Mapping
测试生成字符串:
对于双向一对一关联,实际就是设置IOneToOneMapper,ConfORM会在IPatternsAppliersHolder的OneToOne和OneToOnePath集合中匹配对应模式适配器,即匹配到以下三个模式适配器,进行相应操作。
BidirectionalPrimaryKeyAssociationMasterOneToOneApplier:应用IOneToOneMapper.Cascade(Cascade.All)
BidirectionalOneToOneAssociationPoidApplier:应用IIdMapper.Generator(Generators.Foreign(BidirectionalOneToOneOrNull(subject.ReflectedType)))
BidirectionalPrimaryKeyAssociationSlaveOneToOneApplier:应用IOneToOneMapper.Constrained(true)
双向一对一外键关联(Bidirectional one-to-one (foreign key association))
Domain与双向一对一主键关联(Bidirectional one-to-one (primary key association))相同。
2.ConfORM
配置Domain,注意黑体:
[Test]public void BidirectionalOneToOneMappingDemo2(){//show how work with one-to-one and how ConfORM understands OOPvar orm = new ObjectRelationalMapper();var mapper = new Mapper(orm);var entities = new[] { typeof(Person), typeof(Address) };//use the definition of table-to-class strategy class by classorm.TablePerClass(entities);// Defining relationsorm.ManyToOne<Person, Address>(); orm.OneToOne<Address, Person>();// Show the mapping to the consolevar mapping = mapper.CompileMappingFor(entities);Console.Write(mapping.AsString());}
3.Mapping
测试生成字符串:
类似的,匹配到以下模式适配器:
BidirectionalForeignKeyAssociationManyToOneApplier:应用IManyToOneMapper.Unique(true)和IManyToOneMapper.Cascade(Cascade.All)
BidirectionalForeignKeyAssociationOneToOneApplier:应用IOneToOneMapper.PropertyReference(GetPropertyOf(manyToOneSideType, oneToOneSideType))
BidirectionalPrimaryKeyAssociationMasterOneToOneApplier:应用IOneToOneMapper..Cascade(Cascade.All)
结语
这篇文章展示ConfORM的One-to-One语义应用,映射了三种One-to-One映射。
参考资料
Fabio Maulo:ConfORM:“Mapping” One-To-One