Accessing before and after rows
Many trigger actions need to access the values of the rows being
Such trigger actions need to know one or both of the following:
- the "before" values of the rows being changed (their values before the
database event that caused the trigger to fire)
- the "after" values of the rows being changed (the values to which the
database event is setting them)
Derby provides transition
variables and transition tables for a trigger action to access these values.
See "Referencing Old and New Values: The Referencing Clause" in the Java DB Reference Manual.