![]() The only rows affected by this clause are those rows in the destination table that are updated by the merge operation. Specify the DELETE where_clause to clean up data in a table while populating or updating it. If the condition is not true, then the database skips the update operation when merging the row into the table. The condition can refer to either the data source or the target table. Specify the where_clause if you want the database to execute the update operation only if the specified condition is true. ![]() If the update clause is executed, then all update triggers defined on the target table are activated. Oracle performs this update if the condition of the ON clause is true. The merge_update_clause specifies the new column values of the target table. Refer to Oracle Database Security Guide for more information on enforcing policies on specific SQL statement types. ADD_POLICY statement_types parameter, include the INSERT, UPDATE, and DELETE statements, or just omit the statement_types parameter altogether. Beginning with Oracle Database 11 g Release 2 (11.2.0.2), you can create policies on applications that include MERGE INTO operations. In previous releases of Oracle Database, when you created an Oracle Virtual Private Database policy on an application that included the MERGE INTO statement, the MERGE INTO statement would be prevented with an ORA-28132: Merge into syntax does not support security policies error, due to the presence of the Virtual Private Database policy. If the condition is not true for any rows, then the database inserts into the target table based on the corresponding source table row. For each row in the target table for which the search condition is true, Oracle Database updates the row with corresponding data from the source table. Use the ON clause to specify the condition upon which the MERGE operation either updates or inserts. The source can be a table, view, or the result of a subquery. Use the USING clause to specify the source of the data to be updated or inserted. Restriction on Target Views You cannot specify a target view on which an INSTEAD OF trigger has been defined. Refer to "Notes on Updatable Views" for more information. In order to merge data into a view, the view must be updatable. Use the INTO clause to specify the target table or view you are updating or inserting into.
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