I've go this request in SQL for a migration:
UPDATE table1
SET table1.value = table2.value
FROM table1
INNER JOIN table2
ON table2.othervalue2 = table1.key
WHERE table2.othervalue3 is NULL
Works well. But not with Oracle. I know it isn't impossible to make join in a update with oracle, so I use this:
UPDATE table1 SET table1.value = (SELECT table2.value
FROM table2
WHERE table2.othervalue2 = table1.key
AND table2.othervalue3 is NULL)
WHERE EXISTS (SELECT table2.value
FROM table2
WHERE table2.othervalue2 = table1.key
AND table2.othervalue3 is NULL)
but I have an ORA-01427: Subquery returns more than one row.
Thanks