子查询的应用

/* Formatted on 2007/12/20 18:12 (Formatter Plus v4.8.8) */
SELECT *
  FROM (SELECT w.workitem_id, 
               w.m_id, 
               w.process_def_id, 
               w.process_def_name,
               w.process_ins_id, 
               w.process_ins_name, 
               w.activity_ins_id,
               w.activity_ins_name, 
               w.TYPE, 
               w.created_time, 
               w.participant,
               w.start_time, 
               w.time_unit, 
               w.time_limit, 
               w.attachment_id,
               w.form_id, 
               w.app_id, 
               w.activity_list, 
               w.completed_time,
               i.description, 
               w.state, 
               w.prestate, 
               i.parent_process_ins_id,
               i.parent_activity_ins_id, 
               m.process_file_path,
               a.activity_def_id,
               (SELECT d.data_value
                  FROM ctais2wg.t_relevant_data d,
                       ctais2wg.t_model_global_data g
                 WHERE d.process_ins_id = i.process_ins_id
                   AND g.m_id = a.m_id
                   AND g.process_def_id = a.process_def_id
                   AND g.NAME = 'wf_keyword'
                   AND d.data_id = g.data_id) AS data_value
          FROM ctais2wg.t_workitem w,
               ctais2wg.t_process_ins i,
               ctais2wg.t_process_def_manage m,
               ctais2wg.t_activity_ins a
         WHERE i.process_ins_id = w.process_ins_id
           AND m.process_id = w.process_def_id
           AND (w.state = 1 OR w.state = 2)
           AND (w.TYPE = 1 OR w.TYPE = 2)
           AND a.process_ins_id = w.process_ins_id
           AND a.activity_ins_id = w.activity_ins_id
           AND a.m_id = w.m_id
           AND w.participant = 401004928)
 WHERE data_value LIKE '%延期申请书%'