ORA-01779 cannot modify a column which maps to a non key-preserved table

Cause --

1. Query cannot update the query, because XXMAX_TRANSACT_QTY is a view, created by multiple tables.

   FROM mtl_onhand_lot_new_v     moqd,

   mtl_lot_numbers          mln,

   mtl_system_items_b       mtl,

2.  An attempt was made to insert or update columns of a join view which map to a non-key-preserved table.

BEGIN

   UPDATE APPS.XXMAX_TRANSACT_QTY

      SET ACTUAL_GSM = ''

    WHERE     LOT_NUMBER = '130921-0302-13440-9101'

          AND ORGANIZATION_ID = '103'

          AND GEN_OBJECT_ID = '5458047';

   COMMIT;

END;

Trouble Shooting

Action: Modify the underlying base tables directly.