Oracle trigger if updating then
Data definition types of triggers can be used to capture events related to DDL statements such as create, drop, and alter. If you do not use LONG or LONG RAW data types, any restrictions concerning these are transparent to you.
Oracle places a size limit of 32KB on a trigger statement. Up to the question mark, this article used about 25KB, using around 870 words and over 4,000 characters, just to give you a rough idea of how much code you can write under 32KB. Several other restrictions and one interesting restriction has to do with the order in which triggers are fired.
See here why triggers are nor the best choice for data validation A trigger is like an IDMS user exit, an opening in the code where you can branch out and "do your own thing", prior to performing the insert, update or delete.
PUT_LINE('You Just Updated a Row Mr.'