Defines the representation of a type in the underlying relational database system and/or provides information to map its members.

type

A class name. The class name can either be the full qualfied name or the short name of a type.

extent-provider

One of the type extent providers providing the storage model of the type in the underlying relational database system. When the type is a persistent type, specifying the extent-provider is obligatory.

object-identity

An object identity provider specifying how instances of the type are identified in the underlying relational database system. When the type is a root type of a type family, specifying the object-identity is obligatory.

type-identity

A type identity provider specifying how to map the runtime-type information of type in the underlying relational database system. When the type is a root type of a type family, specifying the type-identity is obligatory.

proxy-provider

One of the proxy providers defining the proxy model of the type. The proxy-provider has to be specified for non-abstract persistent types.

member-mappings

Zero or more <Member>, <DefineProperty> or <DefineMethod> element used to define the mapping of individual members of type in the underlying relational database system.

type-modifier

Other custom elements that can extend the functionality of the type.

Remarks

The <Type> element is used to specify the representation of object state in the underlying relational database system for persistent types. The type mapping can be conducted by the schema's author by using several building blocks provided by Genome :

• type extent provider - specifies how the fields of the type are stored in the underlying relational database system.
• object identity provider - specifies how the instances of the type are identified.
• type identity provider - specifies how to map the runtime-type information of type instances into the database.
• proxy provider - defines the proxy model of the type. The proxy provider has to be specified on non-abstract persistent types.

The <Type> element can also contain the member mapping elements, which specify the mapping between the behaviour of individual members and the natural language of the underlying relational database system. Not all members necessarily need to be mapped in the schema definition file.

The root type of a type is the first ancestor which has an associated table in the underlying relational database system. The root type is not necessarily the root of the class hierarchy, but the base types of the root type are not stored in the underlying relational database system. Each root type defines a type family that consists of the root type and all its descendants in the inheritance tree. Several behavioural aspects in Genome are specified for whole type families.

Requirements

Type: TechTalk.Genome.Schema.Builder.Xml.TypeXmlData

Assembly: TechTalk.Genome.dll

Version: 4.2.4

Editions: Professional, Evaluation, Express

Database Platforms: Microsoft SQL Server 2000, Microsoft SQL Server 2005, Oracle 9i Release 2, Oracle 10g Release 2

See Also

Type Extent Providers | Object Identity Providers | Type Identity Providers | Proxy Providers | <Member> Element