About Generating from Offline Database Definitions

The Generate SQL from Offline Database Objects wizard allows you to choose how to update a database schema with the offline tables and views that you have created or edited. You can:

Create or replace the tables and views in the database. If you choose to generate a SQL file, it will contain CREATE and DROP statements. See Generating Database Definitions to a File and Generating Database Definitions to a Database.
Update existing database schema objects with the changes you have made to the offline database objects. JDeveloper first reconciles the offline database definitions against the objects in the database schema to identify the changes necessary. If you choose to generate a SQL file, it will contain ALTER statements. See Reconciling Changes and Generating Database Definitions to a File and Reconciling Changes and Generating Database Definitions to a Database.

Whether you are generating changes to a database, or the reconciling changes, you can choose to:

Generate a SQL file that you can examine, and run against the database later.
Make the changes directly to the database.
Make the changes to the database and also generate a SQL file.

Alternatively, if you just want to generate one or more offline tables back to the database connection they were originally imported from, you can do this directly from the navigator. See Fast Generate or Reconcile to a Database Connection.

Note: If you have made changes to tables that have foreign keys, it is possible that the foreign keys will be dropped when you generate your changes to the database. For more information, refer to Offline Tables and Foreign Keys.

Reconciliation Issues

Cannot Modify Constraints

Constraints can be created or dropped during reconciliation; they cannot be modified. The only ALTER TABLE reconciliations that can be performed are ADD CONSTRAINT, DROP CONSTRAINT , ADD COLUMN, DROP COLUMN, and WIDEN COLUMN .

Cannot Reconcile Renamed Tables

You can change the name of a table when you import it or while you are editing it offline. If you try to reconcile the renamed table back to the database, you will receive an error message because the database does not have a record of the table with its new name.

To avoid this, create the renamed table in the database, do not reconcile or replace it.