Update Query working on SQl server not on Oracle

[Arvinder Sahni]

UPDATE
     jt
SET 
    jt.Assigneduser = (SELECT u.userid FROM Users u where u.username ='Debbie Ross')
FROM
   Jobstasks jt
    Users u on jt.assigneduser = u.userid
   Funds f on  jt.fundid = f.fundid
     Jobs j on jt.procindex = j.procindex
    Tasks t on jt.taskindex = t.taskindex 
WHERE
     j.jobdescription = 'UnderWriting - Insurance Submission'
     and (
         T.Taskdescription = 'Review/Check Documents for Assessment'
         or jt.tasksequence = 2
     )
     and f.dbcode = 'FBRPW'
     and f.subfund = 'FBRP'
     and (u.username = 'Debbie Ross'
         or jt.assigneduser is NULL)
     and jt.inactivejobtask = 'N';

The above query is working on SQL server not on Oracle PL/SQL. Can someone please help?

[Rabbit]

It would help if you explained what "not working" means. Are there error codes? Is it updating the wrong rows? It it not updating any rows? If there are error messages, what are they?

Also, that query won't run on SQL Server either... you never specify the join clause. It will error out in SQL Server.

[arunnarang]

kINDLY GIVE THE STRUCTURE AND DATA OF TABLE