[code]
SELECT DISTINCT( b.transactionid ), 
               b.eoawthread_id, 
               c.oprid, 
               a.business_unit, 
               a.req_id 
FROM   psworklist c 
       JOIN ps_eoaw_wl b 
         ON b.busprocname = c.busprocname 
            AND b.activityname = c.activityname 
            AND b.eventname = c.eventname 
            AND b.worklistname = c.worklistname 
            AND b.instanceid = c.instanceid 
            AND b.transactionid = c.transactionid 
       JOIN ps_pv_req_aw a 
         ON a.eoawprcs_id = b.eoawprcs_id 
            AND a.eoawdefn_id = b.eoawdefn_id 
            AND b.eoawthread_id = a.eoawparent_thread 
            AND a.eoawprcs_id = b.eoawprcs_id 
            AND a.eoawdefn_id = b.eoawdefn_id 
            AND a.eoawthread_status IN ( 'A', 'C', 'D', 'N', 
                                         'T', 'S' ) 
       JOIN ps_req_line l 
         ON a.req_id = l.req_id 
            AND a.business_unit = L.business_unit 
            AND l.curr_status <> 'P' 
            AND c.inststatus = 1 
            AND c.busprocname = 'EOAW_APPROVALS' 
            AND c.activityname = 'EOAW_ROUTE' 
            AND a.req_id = '0003106027' 
            AND A.business_unit = 'PS001'
[/code]

Output:
transactionid   eoawthread_id  oprid    business_unit  req_id
3098587	        26294531	   U271895	PS001	       0003106027
3098588	        26294531	   A173236	PS001	       0003106027

[code]
UPDATE psworklist 
SET    psworklist.inststatus = 2 
WHERE  EXISTS (SELECT DISTINCT C.transactionid 
               FROM   psworklist c 
                      JOIN ps_eoaw_wl b 
                        ON b.busprocname = c.busprocname 
                           AND b.activityname = c.activityname 
                           AND b.eventname = c.eventname 
                           AND b.worklistname = c.worklistname 
                           AND b.instanceid = c.instanceid 
                           AND b.transactionid = c.transactionid 
                      JOIN ps_pv_req_aw a 
                        ON a.eoawprcs_id = b.eoawprcs_id 
                           AND a.eoawdefn_id = b.eoawdefn_id 
                           AND b.eoawthread_id = a.eoawparent_thread 
                           AND a.eoawprcs_id = b.eoawprcs_id 
                           AND a.eoawdefn_id = b.eoawdefn_id 
                           AND a.eoawthread_status IN ( 'A', 'C', 'D', 'N', 
                                                        'T', 'S' ) 
                      JOIN ps_req_line l 
                        ON a.req_id = l.req_id 
                           AND a.business_unit = L.business_unit 
                           AND l.curr_status <> 'P' 
                           AND c.inststatus = 1 
                           AND c.busprocname = 'EOAW_APPROVALS' 
                           AND c.activityname = 'EOAW_ROUTE' 
                           AND a.req_id = '0003106027' 
                           AND A.business_unit = 'PS001')
[/code]