Java Programming with Oracle JDBC

Transaction Scope

An existing transaction ends, and a new transaction starts, at the moment a commit or rollback command is issued. Assuming you’ve turned off auto-commit, a COMMIT statement makes permanent any changes you’ve made to the database using INSERT, UPDATE, or DELETE statements since the last time a COMMIT or ROLLBACK statement was executed. With JDBC, commit your changes manually by calling the Connection object’s commit( ) method. Calling the commit( ) method sends a COMMIT to the database. The commit( ) method takes no arguments but may throw an SQLException. However, it’s very rare for a commit to result in an exception. For example, to commit changes for the Connection named conn, use the following code:

conn.commit(  );

On the other hand, a rollback command irrevocably discards, or undoes, any INSERT, UPDATE, or DELETE statements you’ve executed since the last time a COMMIT or ROLLBACK statement was executed. To roll back, use the Connection object’s rollback( ) method. For example, to roll back updates to the database made using the Connection named conn, use the following code:

conn.rollback(  );

One last note: while auto-commit is off, if a Connection is closed without committing or rolling back, or if any DDL is executed, then any uncommitted changes are automatically committed.