Trigger variables v16
In the trigger code block, several special variables are available for use.
NEW
NEW is a pseudo-record name that refers to the new table row for insert and update operations in row-level triggers. This variable doesn't apply to statement-level triggers and delete operations of row-level triggers.
Its usage is:
:NEW.column
Where column is the name of a column in the table where the trigger is defined.
The initial content of :NEW.column is the value in the named column of the new row to insert. Or, when used in a before row-level trigger, it's the value of the new row that replaces the old one. When used in an after row-level trigger, this value is already stored in the table since the action already occurred on the affected row.
In the trigger code block, you can use :NEW.column 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 is used in the new inserted or updated row.
OLD
OLD is a pseudo-record name that refers to the old table row for update and delete operations in row-level triggers. This variable doesn't apply 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 delete or of the old row to replace with 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 already occurred on the affected row.
In the trigger code block, you can use :OLD.column like any other variable. Assigning a value to :OLD.column has no effect on the action of the trigger.
INSERTING
INSERTING is a conditional expression that returns TRUE if an insert operation fired the trigger. Otherwise it returns FALSE.
UPDATING
UPDATING is a conditional expression that returns TRUE if an update operation fired the trigger. Otherwise it returns FALSE.
DELETING
DELETING is a conditional expression that returns TRUE if a delete operation fired the trigger. Otherwise it returns FALSE.