Creating Updatable View Objects (continued)
The Query page of the wizard enables you to see the SQL query that is generated and to set WHERE and ORDER BY clauses for it. There are buttons for Explain Plan and to Test the query.
The Query page has three modes of operation:
Normal mode is easier and more foolproof, because most of the query is taken care of for you. The SELECT and FROM portions of the SQL statement are automatically created, based on the entity objects that the view object is based on, and on view attributes with the Selected in Query setting. You can add the WHERE and ORDERBY portions of the query as needed.
Expert mode is useful if:
You want complete control over the SQL query, such as the SELECT and FROM portions. In this mode, you are responsible for ensuring that the mapping of SQL result columns to entity attributes is correct in the Attribute Mappings page. You need to remap these items if you deleted, added, or switched positions of columns in your custom SQL query, because the mappings might no longer be correct.