Changes are automatically committed during DML operations, which is called the auto-commit mode.
You can disable the auto-commit mode by calling the following method on the Connection object:
conn.setAutoCommit(false);
If the auto-commit mode is disabled, you must call the following method on the Connection object to commit the changes:
conn.commit();
You can also run the following command to roll back the changes:
conn.rollback();
The COMMIT or ROLLBACK operation affects all DML statements executed since the last COMMIT or ROLLBACK operation. Note
An DDL operation will eventually result in an implicit COMMIT operation. If the auto-commit mode is disabled, the implicit COMMIT operation implicitly commits the DML operations that have not been explicitly committed or rolled back.