CLR User-defined Types

The introduction of user-defined types (UDTs) in SQL Server 2005 allows you to extend the scalar type system of the server, enabling storage of CLR objects in a SQL Server database. UDTs can contain multiple elements and can have behaviors, differentiating them from the traditional alias data types which consist of a single SQL Server system data type.

Because UDTs are accessed by the system as a whole, their use for complex data types may negatively impact performance. Complex data is generally best modeled using traditional rows and tables. UDTs in SQL Server 2005 are well suited to the following:

Date, time, currency, and extended numeric types
Geospatial applications
Encoded or encrypted data

PowerDesigner models user-defined types as abstract data types.

User-defined Type Properties

You can modify an object's properties from its property sheet. To open a user-defined type property sheet, double-click its diagram symbol or its Browser entry in the Abstract Data Types folder.

In addition to the standard abstract data type properties, a user-defined type has the following additional properties available on the Microsoft tab:

Name	Description
Assembly	Specifies the assembly to bind with the abstract data type. Scripting name: Assembly
Mandatory	Specifies whether the type can hold a null value. Scripting name: Mandatory

Name

Description

Assembly

Specifies the assembly to bind with the abstract data type.

Scripting name: Assembly

Mandatory

Specifies whether the type can hold a null value.

Scripting name: Mandatory