Adding a View Object Instance with a New SQL-only Definition at Runtime

You can dynamically define a new view object and add an instance of it to an application module's data model at runtime by calling createViewObjectFromQueryStmt() on the application module.

Note: The view object instance you create will have no entity usages; that is, all of its attributes will be transient. For more information, or to add an instance of a view object with entity usages, see the Related topics list.

To add a view object instance with a new SQL-only definition at runtime:

Create a String containing the name you want to give the instance in the data model. For example, if this instance is to be called OrdersForCustomer, you would use the following code:
String voInstanceName = "OrdersForCustomer";
Create a String containing the query for the view object. Do not include a semicolon in the String:
String query = "SELECT * FROM ORDERS";

Call createViewObjectFromQueryStmt() passing in the instance name and the query:

ViewObject ordVO = 
  myAM.createViewObjectFromQueryStmt(voInstanceName, query);

If you want the instance to stand in a master-detail relationship with another instance, see Ways to Change View Object Relationships at Runtime.

Note: If you create a view object using this method, the query may be executed twice the first time you fetch data. The first query collects data type and precision information, which is used in subsequent queries to map data to the proper Java types and make the query more efficient (by specifying precision where it is below the maximum). For expensive queries, where executing twice causes a performance problem, you may want to create the view object with a "dummy" where clause that returns no rows, call getAttributeCount() on the view object to facilitate the metadata query and attribute definition, and then call setQuery() to change the query to the one you want. This way, the initial query is a trivial, and far less expensive, query on the same dataset.