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4 Triggers : 4.4 Trigger Variables

NEW is a pseudo-record name that refers to the new table row for insert and update operations in row-level triggers. This variable is not applicable in statement-level triggers and in delete operations of row-level triggers.
Its usage is: :NEW.column where column is the name of a column in the table on which the trigger is defined.
The initial content of :NEW.column is the value in the named column of the new row to be inserted or of the new row that is to replace the old one when used in a before row-level trigger. When used in an after row-level trigger, this value has already been stored in the table since the action has already occurred on the affected row.
In the trigger code block, :NEW.column can be used like any other variable. If a value is assigned to :NEW.column, in the code block of a before row-level trigger, the assigned value will be used in the new inserted or updated row.
OLD is a pseudo-record name that refers to the old table row for update and delete operations in row-level triggers. This variable is not applicable in statement-level triggers and in insert operations of row-level triggers.
Its usage is: :OLD.column where column is the name of a column in the table on which the trigger is defined.
The initial content of :OLD.column is the value in the named column of the row to be deleted or of the old row that is to be replaced by the new one when used in a before row-level trigger. When used in an after row-level trigger, this value is no longer stored in the table since the action has already occurred on the affected row.
In the trigger code block, :OLD.column can be used like any other variable. Assigning a value to :OLD.column, has no effect on the action of the trigger.
INSERTING is a conditional expression that returns true if an insert operation fired the trigger, otherwise it returns false.
UPDATING is a conditional expression that returns true if an update operation fired the trigger, otherwise it returns false.
DELETING is a conditional expression that returns true if a delete operation fired the trigger, otherwise it returns false.

4 Triggers : 4.4 Trigger Variables

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