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oracle adf workshop

Notes:


Characteristics of Updatable View Objects

So far you have learned to create view objects that are based on an SQL query. Such view objects can be used by client applications to present data in read-only mode.

You have also learned that the entity object is the ADF BC mechanism to interact with the database, enabling inserts, updates, and deletes. However, entity objects are not visible to client applications.

To retrieve and present to the client application the records to be updated, you need a different type of view object, one that is based on an entity object rather than on an SQL query. This is called an updatable view object.

The slide shows an example of a view object, called CustomerStatusVO. An updatable view object is bound to an entity object; this one is based on the CustomerEO entity object. A view object’s attributes map to the attributes of the underlying entity object; the CustomerStatusVO view object has attributes that map to the Name and Status attributes of the underlying entity object.

Even though an updatable view object is based on an entity object, it still uses a SQL query (select) to sort and filter data, so you can specify ORDER BY and WHERE clauses for it.