Update and Merge Statement for Oracle

Update based on a query returning multiple values

UPDATE <table_name> <alias>
SET (<column_name>,<column_name> ) = (
SELECT (<column_name>, <column_name>)
FROM <table_name>
WHERE <alias.column_name> = <alias.column_name>)
WHERE <column_name> <condition> <value>;

Update the results of a SELECT statement

UPDATE (<SELECT Statement>)
SET <column_name> = <value>
WHERE <column_name> <condition> <value>;

http://psoug.org/reference/update.html

Merge Statement Demo

MERGE <hint> INTO <table_name>
USING <table_view_or_query>
ON (<condition>)
WHEN MATCHED THEN <update_clause>
DELETE <where_clause>
WHEN NOT MATCHED THEN <insert_clause>

http://psoug.org/reference/merge.html