Error Reason

Hi All,

I am running below query & getting error (appended below). Please guide why the said error is appearing? I tried but failed to have reason & ultimately to rectify the same.

SQL> Declare cursor c_item_keys is SELECT we.item_key error_key

  FROM wf_items we

  , wf_item_activity_statuses weias

  , wf_notifications wfn

  WHERE we.item_type = 'POERROR'

  AND weias.item_type = we.item_type

  AND weias.item_key = we.item_key

  AND wfn.GROUP_ID = weias.notification_id

  AND we.parent_item_type = 'POAPPRV'

  AND wfn.end_date IS NULL

  and we.end_date IS NULL