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If you want to update specific rows (ie where the IDs match) you probably want to do a coordinated subquery. However, since you are using Oracle, it might be easier to create a materialized view for your query table and let Oracle's transaction mechanism handle the details.
6 gru 2017 · UPDATE Subquery. Finally, you can use a subquery in an UPDATE statement for the table to be updated. In the previous examples, we have just used the product table. However, you can use a subquery instead of the product table, which will return a result set that can be updated.
Subquery Method. The first option is to do an update of the DEST_TAB table using a subquery to pull the correct data from the SOURCE_TAB table. Notice the EXISTS predicate to exclude rows from the DEST_TAB table with no matching row in the SOURCE_TAB table.
16 maj 2013 · update table_a upd set upd.col1 = ( select sub.col2 from ( select rownum as row_number, b.col2 as col2, b.col3 as col3 from table_a a, table_b b where b.col3 = a.col4 ) sub where sub.row_number = 2 and sub.col3 = upd.col4 )
5 gru 2014 · Essentially you create a table type, then create a variable with that table type, then do a select for update to get all of the data that you want to update, then do a forall update to update the data.
This statement uses a correlated subquery to update a single column across multiple rows in the FLIGHTS table. It increases the duration of all BA flights by thirty minutes. The subquery returns all flights with OPERATING_CARRIER_CODE set to 'BA'.
It sounds like you are trying to update a table T1 with data from T2 and you are using a query like: update T1 set c1 = ( select c2 from T2 where T2.key = T1.key ) where exists ( select c2 from T2 where T2.key = T1.key ) / correct?
