Custom Properties
Topic Last Modified: 2006-06-12
Although the Exchange store provides a large number of predefined properties used for standard applications, you can store any number of additional properties along with each item; these are called custom properties. Each item can have a completely different set of custom properties that you define.
A custom property is stored with its associated item and can be requested by name when examining the item. When you bind directly to items using the Exchange OLE DB (ExOLEDB) provider or Microsoft® ActiveX® Data Objects (ADO), or when you issue a PROPFIND Method with a depth of 0 through the WebDAV protocol, the Exchange store returns all custom properties for the item. Custom properties are not visible to The SELECT * Statement or a PROPFIND Method for all item properties with a depth of 1 unless they are defined as part of the item's content class. Therefore, to make your properties discoverable to schema-aware applications such as the Exchange store query processor, you must add property and content class definitions to the application folder's schema scope.
When searching for custom properties using a Structured Query Language (SQL) statement, you should use the CAST Function for all properties that are not of the string type. Custom properties should be cast in both the SELECT Statement and the WHERE Clause portions of the SQL statement.