Views with "instead of" triggers

Sometimes in Infor Public Sector there is a need to create agency business objects that can access tables in other databases or systems. This can be accomplished by creating the agency business object and then associating it with a database view. Depending on the purpose, the view can be either read-only or updatable. The underlying tables for the view can come from any type of data.

The general procedure is outlined below.

1. In the Schema Manager, define an agency table with a table type of “View.” Use the Synchronize command to generate the business object.
2. Create a database view that mimics the structure you defined in the Schema Manager. You can have additional columns, but you must include all that are defined in the business object. Creating a view in the Schema Manager doesn’t create the actual view in the database, just the business object that will interact with the view.
3. Create an “instead of” trigger on the view. If you want it to be read-only then point everything to NULL, as shown in the first example below. If you want some columns to be updatable then code in the update.