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Does an on UPDATE trigger have access to old and new variables?
A trigger fired by an UPDATE statement has access to both old and new column values for both BEFORE and AFTER row triggers.
What is referencing new as new old as old in Oracle trigger?
Referencing old and new values: the referencing clause Changed data can be referred to in the triggered-SQL-statement using transition variables or transition tables. INSERT row triggers cannot reference an OLD row. DELETE row triggers cannot reference a NEW row.
Can we use trigger old in after insert?
WITH After Insert, TRIGGER. OLD and TRIGGER. OLDMAP will not be available as we do not have any old data available. This is a new record that is inserted into the database.
When to use instead of trigger in Oracle?
Users write normal UPDATE, INSERT, and DELETE statements against the view, and the INSTEAD OF trigger works invisibly in the background to make the right actions take place. By default, INSTEAD OF triggers are activated for each row (see “FOR EACH ROW Option” on page 13-7). Views That Are Not Modifiable
When to use trigger in insertor deletetriggering statement?
If a triggering statement includes a column list, the trigger is fired only when one of the specified columns is updated. If a triggering statement omits a column list, the trigger is fired when any column of the associated table is updated. A column list cannot be specified for INSERTor DELETEtriggering statements.
Can a trigger change the name of a column?
Because the trigger uses the BEFOREkeyword, it can access the new values before they go into the table, and can change the values if there is an easily-corrected error by assigning to :NEW.column_name.
When to use a trigger in an UPDATE statement?
An UPDATE statement might include a list of columns. If a triggering statement includes a column list, the trigger is fired only when one of the specified columns is updated. If a triggering statement omits a column list, the trigger is fired when any column of the associated table is updated.