C.2 Query Processing

Table C-2 ADF Equivalents for Oracle Forms Query Processing Triggers

Forms Trigger	ADF Equivalent
PRE-QUERY Execute logic before executing a query in a Data Block, typically to setup values for query-by-example criteria in the "example record".	Override executeQueryForCollection() on your view object class and write code before calling the super.
ON-COUNT Override default behavior to count the query hits for a Data Block	Override getQueryHitCount() in your view object and do something instead of calling the super.
POST-QUERY Execute logic after retrieving each row from the datasource for a data block.	Generally instead of using a POST-QUERY style technique to fetch descriptions from other tables based on foreign key values in the current row, in ADF it's more efficient to build a view object that has multiple participating entity objects, joining in all the information you need in the query from the main table, as well as any auxiliary/lookup-value tables. This way, in a single round-trip to the database you get all the information you need. If you still need a per-fetched-row trigger like POST-QUERY, override the createInstanceFromResultSet() method in your view object class.
ON-LOCK Override default behavior to attempt to acquire lock on the current row in the data block.	Override the lock() method in your entity object class and do something instead of calling the super.