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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.
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.
6 Δεκ 2017 · Using a subquery in an UPDATE statement can be a good way to improve the maintainability of your queries. It can also reduce the number of steps required to update your data by compressing two or more queries into a single query.
4 Αυγ 2023 · Direct join syntax is unsupported in Oracle Database; use a correlated subquery to fetch the values instead. For example: update nashvillehousing a set propertyaddress = ( select nvl2(a.propertyaddress, b.propertyaddress,b.propertyaddress) from nashvillehousing b where a.parcelid = b.parcelid and a.uniqueid_ != b.uniqueid_ ) where a ...
5 Δεκ 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.
10 Μαΐ 2012 · update tabl a. set (a.c1) = (select sum(c1) from ( select c1,a1,b1 from t1,t2,t3 where .. some joins)). This query need to be aliased so that I can check with the. table to be updated with the key values. update tabl a. set (a.c1) = (select sum(c1) from ( select c1,a1,b1 from t1,t2,t3 where .. some joins))qry.
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'.
