Notes This page last changed on Sep 10, 2007 by salexand. original .. from Manage Entity Data Service Keys ## Original Data service keys are used in conjunction with create-update-delete operations. Techniques for creating and managing a key depend on the nature and state of your data service. ##### Methods of Creating Entity Data Service Keys
Schema Key Creation Method | Details
--- | ---
Imported | When a physical data service is created from a relational source metadata keys, if any, are imported with other metadata.
Manually | You can create a key for any entity data service that contain a Read function. The key is created by selecting data service elements.
Automatically | In some situations a key can be inferred from the components of a logical data service.
There are several things to keep in mind related to the creation and management of data service keys including: Only one key can be associated with an entity data service containing a valid read function. Keys are represented in your dataspace project as schema (XSD) file: dataserviceName-KEY.xsd Each time a project is built its dataspace key schemas are validated. The proper definition of a key requires specific knowledge of your data as well as a good understanding of the update map being planned for the functions in the data service. ## Accessing Key Management Routines To access the key management functionality of your data service: Open your data service in Eclipse Right-click in the work area or on the title line of the data service Select Manage Keys... ## Inspecting a Data Service Key Once you have accessed the Select Manage keys option if the right-click menu option Delete Key is available, it means that a key is currently associated with your data service. You can inspect an existing key by: Opening the key schema file. ##### Inspecting a Key Schema Double-clicking on the key element. ##### Elements in a Key Element ## Associating a Key Schema with a Data Service You can associate a key schema with your data service: By generating a new schema. By selecting an existing schema type. ### Associating a Schema as a Data Service Key Generally speaking, a key should be defined in such a way that it provides sufficient uniqueness to allow an update operation to identify the exact target tuple. This page support two options: Generating a new key schema. Associating an existing key schema with the current data service. #### Generating a New Key Schema ##### Generate a New Schema Dialog Options
Option | Action | Comment/Reference
--- | --- | ---
Generate a new schema | Select | Select this option if you want to create a new key schema using the wizard.
Directory: | select a directory | Select any directory in your dataspace project.
File Name: | name of key schema | Recommended name is in the form: dataserviceName-KEY.xsd
Global Element: | read only | Displays the name of the global element in the generated key schema. The global element name is determined by the wizard and typically matches the name of the associated data service.
| Next | Proceed to selecting elements for the key.
### Associating an existing key schema with the current data service There are several situations where you might want to select an existing key schema for a data service: The schema is created externally. The schema was previously created but is not currently associated with the data service. To select an existing key schema: Choose the select an existing schema type option Browse to the location of your schema Choose a key schema from inside your project. Key schema are identified with a _KEY appended to the name of the data service such as:
    CUSTOMER_KEY.xsd
Select a global element if the schema contains more than one. ##### Generate a New Schema Dialog Option
Option | Action | Comment/Reference
--- | --- | ---
Select an existing schema type | Select | Select this option if you have an existing key schema that you want to associate with your data service.
File Name: | Browse and select | Select a valid key schema in your dataspace. Key schema are often identified with a _KEY appended to the name of the data service.
Select Global Element: | Select global element | If the identify key schema has more than one global elements, select.
Selector: | n/a | Displays the selector element in the key schema.
| Finish | Completes association
## Specifying Key Fields You can specify key fields in two ways: By auto-generating the key using the primary read function in the logical data service. Manually by selecting the fields that make up the key ### Auto-generating the schema key TBD ### Specifying Key Fields Manually Select the fields that constitute a valid update key for your data service. ##### Specifying Key Fields

Document generated by Confluence on Jan 13, 2009 15:57