How to use multipule join in update stmt

Question

hi,
i have a query in mssql i want to translate it using oracle 11g r2 latest sysntex
UPDATE trips
SET locations = trips.city + ', ' + poi.city
FROM trips INNER JOIN poi
ON poi.trip_guid = trips.guid
where trips.trip_guid =1
UPDATE trips t
SET locations = t.city + ', ' + p.city
FROM poi p
ON p.trip_guid = t.guid
where t.trip_guid =1
please tel me how i can write it in oracel 11g r2
i also show there is mearge statmet is it sql or plsql
yours sincerely

Answer 1

update trips t
set locations = t.city || ', ' ||
(select p.city || e.allow
from poi p
, emp e
where p.trip_guid = t.guid AND e.id = t.id
update trips t
set locations = t.city || ', ' ||
(select p.city || e.allow
from poi p
left join emp e on e.id = t.id
where p.trip_guid = t.guid
1)are these both query same and correct if i want to upate all rows.
2) some body said following two query are different
if there is any theory then pls tel me. because i have to use rownum<2 to get the top most row rather than distinct
in few cases
at some other places.
-- works but look at the number of rows updated
UPDATE test t
SET (tablespace_name, extent_management) = (
SELECT DISTINCT u.tablespace_name, u.extent_management
FROM user_tables a, user_tablespaces u
WHERE t.table_name = a.table_name
AND a.tablespace_name = u.tablespace_name
AND t.table_name LIKE '%A%');
-- works properly
UPDATE test t
SET (tablespace_name, extent_management) = (
SELECT DISTINCT (u.tablespace_name, u.extent_management)
FROM user_tables a, user_tablespaces u
WHERE t.table_name = a.table_name
AND a.tablespace_name = u.tablespace_name)
WHERE t.table_name LIKE '%A%';
yours sincerely
Edited by: 944768 on Feb 20, 2013 5:36 AM
Edited by: 944768 on Feb 20, 2013 5:39 AM