tailieunhanh - Microsoft ADO .NET 4 Step by Step - p 41

Thiết lập này chỉ có tính năng có sẵn để khách hàng dựa trên phiên bản phát hành của các tính năng đó. Ví dụ, khả năng dự án bất động sản trong một truy vấn (với phương pháp mở rộng Chọn) không có sẵn trước khi phiên bản 2. (Phiên bản 2 là mức phát hành hiện tại của văn bản này.) | 376 Microsoft 4 Step by Step This setting indicates which features are available to clients based on the release version of those features. For example the ability to project properties in a query with the Select extension method is not available before Version 2. Version 2 is the current release level as of this writing. For entity permissions the key configuration setting is the AccessRule method as used in the previous example. You pass this method the name of an entity set and a set of rights from the EntitySetRights enumeration. C Customers Visual Basic Customers Call this method for each entity set you plan to make available or use an asterisk as the entity name to simultaneously set rights for all entities at once. Table 22-1 lists the rights available for each entity set. Combine multiple rights together with a bitwise-Or operator to use a combination of rights. table 22-1 Rights Available for Data Service Entities EntitySetRights Member None Description Removes all access rights for the indicated entity set. This is the default for all model entities. ReadSingle ReadMultiple Clients can query a specific entity instance by its primary key. Clients can retrieve a set of all entities in an entity set. This right does not permit selection of an individual entity by primary key although a filter may retrieve similar results. WriteAppend WriteReplace Clients can add new entity records to an entity set. Clients can update entities. When updating an individual entity only those new property values supplied by the client are updated. Other property values are cleared or set to their default values. The client replaces the original record completely. WriteDelete Clients can delete existing entity records. WriteMerge Clients can update entities. When updating an individual entity only those new property values supplied by