\n
![\"DBDiagram\"](\"http:\/\/tpodolak.com\/blog\/wp-content\/uploads\/2013\/03\/fluent-nhibernate-automappings\/DBDiagram.png\")
<\/a>\nModel classes which represent database tables look this way<\/p>\n
\r\npublic abstract class ModelBase\r\n{\r\n public virtual int Id { get; set; }\r\n}\r\n\r\npublic class Project : ModelBase\r\n{\r\n public virtual string Name { get; set; }\r\n public virtual User User { get; set; }\r\n public virtual IList Tasks { get; set; }\r\n}\r\n\r\npublic class Task : ModelBase\r\n{\r\n public virtual string Name { get; set; }\r\n public virtual Project Project { get; set; }\r\n}\r\n\r\npublic class User : ModelBase\r\n{\r\n public virtual string Name { get; set; }\r\n public virtual string Surname { get; set; }\r\n}\r\n<\/pre>\n3. Automappings configuration<\/h3>\n
Having our database and models prepared, now we can create and configure SessionFactory to use automappings.<\/p>\n
\r\nvar factory = Fluently.Configure().Database(MsSqlConfiguration.MsSql2008.ConnectionString(\"YourConnectionString\"))\r\n .Mappings(val => val.AutoMappings.Add(AutoMap.AssemblyOf))\r\n .BuildSessionFactory();\r\n<\/pre>\nAs You can see I used the static AutoMap.AssemblyOf method. This method takes a generic type parameter from which Fluent NHibernate can deduce which assembly to look in for mappable entities. From now all classes defined in the assemlby of Project<\/i> are mapped using build-in convention.<\/p>\n4. Mapping only specified classes<\/h3>\n
Mapping all classes from specyfic assembly may not be very useful. That is why, we need to “tell” Automapper which classes should be mapped. It can be achieved by creating custom configuration class which implements IAutomappingConfiguration<\/i> interface or which is subclass of DefaultAutomappingConfiguration<\/i>. IAutomappingConfiguration<\/i> interface has quite a lot of functions, that is why I decided to craete class which inherits from DefaultAutomappingConfiguration<\/i> and override only one method – ShouldMap<\/i><\/p>\n\r\npublic class AutomappingConfiguration : DefaultAutomappingConfiguration\r\n{\r\n public override bool ShouldMap(Type type)\r\n {\r\n return type.IsSubclassOf(typeof (ModelBase));\r\n }\r\n}\r\n<\/pre>\nAs You can see by overriding ShouldMap<\/i> function,I specified that only classes which inherit from ModelBase<\/i> class should be mapped. To use our new configuration, we need to pass an instance of it to AutoMap setup<\/p>\n\r\nvar factory = Fluently.Configure().Database(MsSqlConfiguration.MsSql2008.ConnectionString(\"YourConnectionString\"))\r\n .Mappings(val => val.AutoMappings.Add(AutoMap.AssemblyOf(new DefaultAutomappingConfiguration())))\r\n .BuildSessionFactory();\r\n<\/pre>\n5. Defining custom conventions<\/h3>\n
It is rather obvious that default automapping conventions may not come along with our database naming conventions. Fortunately we can create custom conventions(which override default ones), and pass them to AutoMap configuration. Here are examples of conventions I use IClassConvention<\/i> – gives us access to properties and functions which allow us to change a default table name format for our entities.<\/p>\n\r\npublic class DefaultTableNameConvention : IClassConvention\r\n{\r\n public void Apply(IClassInstance instance)\r\n {\r\n instance.Table(string.Format(\"{0}{1}\", \"GL_\", instance.EntityType.Name));\r\n }\r\n}\r\n<\/pre>\nIIdConvention<\/i> is used for altering default identity conventions.<\/p>\n\r\npublic class DefaultPrimaryKeyConvention : IIdConvention\r\n{\r\n public void Apply(IIdentityInstance instance)\r\n {\r\n instance.Column(\"Id\");\r\n instance.GeneratedBy.Native();\r\n }\r\n}\r\n<\/pre>\nIPropertyConvention<\/i> – allows us to modify properties mappings (lazy load, nullability,length etc)<\/p>\n\r\npublic class DefaultStringLengthConvention : IPropertyConvention\r\n{\r\n public void Apply(IPropertyInstance instance)\r\n {\r\n instance.Length(50);\r\n }\r\n}\r\n<\/pre>\nIReferenceConvention<\/i> – allows us to modify entities relationship convention<\/p>\n\r\npublic class DefaultReferenceConvention : IReferenceConvention\r\n{\r\n public void Apply(IManyToOneInstance instance)\r\n {\r\n instance.Column(string.Format(instance.Class.Name.StartsWith(\"Id\") ? \"{1}\" : \"{0}{1}\", \"Id\",\r\n instance.Class.Name));\r\n instance.LazyLoad();\r\n }\r\n}\r\n<\/pre>\nIHasManyConvention<\/i> – allow us to modify default has-many relationship convention<\/p>\n\r\npublic class DefaultHasManyConvention : IHasManyConvention\r\n{\r\n public void Apply(IOneToManyCollectionInstance instance)\r\n {\r\n instance.Key.Column(string.Format(\"{0}{1}\", \"Id\", instance.EntityType.Name));\r\n instance.LazyLoad();\r\n }\r\n}\r\n<\/pre>\nIn order to use new conventions we need to pass them into AutoMap configuration.<\/p>\n
\r\nFluently.Configure()\r\n .Database(\r\n MsSqlConfiguration.MsSql2008.ConnectionString(\"YourConnectionString\"))\r\n .Mappings(val => val.AutoMappings.Add(AutoMap.AssemblyOf(new DefaultAutomappingConfiguration()).Conventions.Setup(con =>\r\n {\r\n con.Add();\r\n con.Add();\r\n con.Add();\r\n con.Add();\r\n con.Add();\r\n })))\r\n .BuildSessionFactory();\r\n<\/pre>\n6. Overriding mappings<\/h3>\n
Sometimes it is necessary to slightly modify entity mapping. It can be achieved by creating class which implements IAutoMappingOverride<\/i> interface<\/p>\n\r\npublic class ProjectMapping: IAutoMappingOverride\r\n{\r\n public void Override(AutoMapping mapping)\r\n {\r\n mapping.IgnoreProperty(val=>val.SomeIgnoredProperty);\r\n }\r\n}\r\n<\/pre>\nOverride<\/i> method gives us access to all actions known from fluent mappings. After creating class map, we have to call function UseOverridesFromAssemblyOf<\/i> in our automapping configuration<\/p>\n\r\nvar factory = Fluently.Configure().Database(MsSqlConfiguration.MsSql2008.ConnectionString(\"YourConnectionString\"))\r\n .Mappings(val => val.AutoMappings.Add(AutoMap.AssemblyOf(new DefaultAutomappingConfiguration()).UseOverridesFromAssemblyOf()\r\n .Conventions.Setup(con =>\r\n {\r\n con.Add();\r\n con.Add();\r\n con.Add();\r\n con.Add();\r\n con.Add();\r\n }))).BuildSessionFactory();\r\n<\/pre>\n7. It works<\/h3>\n
Here just couple of screens from NHibernateProfiler with basic queries
\n![\"InsertIntoTask\"](\"http:\/\/tpodolak.com\/blog\/wp-content\/uploads\/2013\/03\/fluent-nhibernate-automappings\/InsertIntoTask.png\")
<\/a>
\n![\"InsertIntoUser\"](\"http:\/\/tpodolak.com\/blog\/wp-content\/uploads\/2013\/03\/fluent-nhibernate-automappings\/InsertIntoUser.png\")
<\/a>
\n![\"InsertIntoProject\"](\"http:\/\/tpodolak.com\/blog\/wp-content\/uploads\/2013\/03\/fluent-nhibernate-automappings\/InsertIntoProject.png\")
<\/a>
\n![\"SelectFromTask\"](\"http:\/\/tpodolak.com\/blog\/wp-content\/uploads\/2013\/03\/fluent-nhibernate-automappings\/SelectFromTask.png\")
<\/a>
\nSource code for this post can be found here<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"1. Introduction Writing mappings for models in large application is quite boring task. Fortunatelly, Fluent NHibernate provides possibility for automatic mapping creation – so called automappings. 2. Creating database and model In order to show you, how to configure automappings in Fluent NHibernate, let’s create simple database along with model classes. The database structure is […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[71,72,3,66],"tags":[214,215,159,209],"class_list":["post-35","post","type-post","status-publish","format-standard","hentry","category-automapper","category-automappings","category-c","category-fluentnhibernate","tag-automapper","tag-automappings","tag-c","tag-fluentnhibernate"],"_links":{"self":[{"href":"https:\/\/tpodolak.com\/blog\/wp-json\/wp\/v2\/posts\/35","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/tpodolak.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/tpodolak.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/tpodolak.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/tpodolak.com\/blog\/wp-json\/wp\/v2\/comments?post=35"}],"version-history":[{"count":4,"href":"https:\/\/tpodolak.com\/blog\/wp-json\/wp\/v2\/posts\/35\/revisions"}],"predecessor-version":[{"id":541,"href":"https:\/\/tpodolak.com\/blog\/wp-json\/wp\/v2\/posts\/35\/revisions\/541"}],"wp:attachment":[{"href":"https:\/\/tpodolak.com\/blog\/wp-json\/wp\/v2\/media?parent=35"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/tpodolak.com\/blog\/wp-json\/wp\/v2\/categories?post=35"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/tpodolak.com\/blog\/wp-json\/wp\/v2\/tags?post=35"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}