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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 Δεκ 2017 · Learn about several methods to update data using subqueries in UPDATE statements to make them more effective and easier to maintain in Oracle SQL.
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.
27 Δεκ 2023 · Before diving into complex examples, let's understand the basic syntax of an update with a join operation in Oracle: sql UPDATE table1 SET table1.target_column = (SELECT table2.source_column FROM table2 WHERE table1.join_column = table2.join_column) WHERE EXISTS (SELECT 1 FROM table2 WHERE table1.join_column = table2.join_column); In the above ...
You may use subqueries in place of tables in this way as well in INSERT, UPDATE, and DELETE statements. Subqueries so used can employ correlation variables, both defined within the subquery itself and those defined in query blocks containing the subquery.
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 ...
23 Φεβ 2012 · In Oracle you can update a join if the tables are "key-preserved", ie: UPDATE (SELECT a.val_a, b.val_b. FROM table a. JOIN table b ON a.b_pk = b.b_pk) SET val_a = val_b. Assuming that b_pk is the primary key of b, here the join is updateable because for each row of A there is at most one row from B, therefore the update is deterministic.
