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Business Components: Read-Only VO


Business Components: Read-Only VO

View Objects with no entity usage definition are always read-only, do not pick up entity-derived default values, do not reflect pending changes, and do not reflect updated reference information. In contrast to entity-based View Objects, read-only View Objects require you to write the query using the SQL query language.

The Create View Object wizard and overview editor for entity-based View Objects, on the other hand, simplify this task by helping you construct the SQL query declaratively. For this reason, it is preferable to create a nonupdatable, entity-mapped VO, even when you want to create a VO just to read data.

To create a nonupdatable VO that is mapped to an EO, perform the following:

1. Create a VO based on an EO.

2. With the EO selected in the Entity Objects panel of the VO editor, deselect the Updatable check box.

Additionally, as an alternative to creating View Objects that specify a SQL statement at design time, you can create entity-mapped View Objects that dynamically generate SQL statements at run time.