Update 1 column,1 single table based on where results of multiple tables

Question

I would like the my_id column in 1 table updated to the static value of 247 for my_id stored in the 1 single table based on the where clause, which uses the my_id column in it.
The update statement updates all rows in table1, instead of just the rows where
the condition ( (b.my_id=a.my_id)
and ( b.my_name like 'OIS SrClerk%')
and (a.f_id=m.f_id)
and (trunc(m.cr_time) < '02-Apr-2008')) is true
What needs to be changed?
update table1 a
set a.my_id=247
from table1 a, table2 b, table3 m
where
(b.my_id=a.my_id)
and ( b.my_name like 'OIS SrClerk%')
and (a.f_id=m.f_id)
and (trunc(m.cr_time) < '02-Apr-2008')

Answer 1

Are you looking for this?
UPDATE table1 A
   SET A.my_id = 247
WHERE EXISTS (SELECT 'x'
                 FROM table2 b,
                      table3 M
                WHERE b.my_id = A.my_id
                 AND b.my_name LIKE 'OIS SrClerk%'
                 AND A.f_id = M.f_id
                 AND TRUNC (M.cr_time) < to_date('02-apr-2008 00:00:00','dd-mon-yyyy HH:MI:SS') )changed date string to to_date
Message was edited by:
devmiral