For example, the following trigger enforces the constraint and nothing would be inserted.
In general, the effects of both the trigger and the triggering statement are rolled back.
Oracle also provides simple error message strings that have a format similar to the following: For more details on how to do error handling, please take a look at Pro*C Error handling or at the Retrieving Exceptions section of JDBC Error handling.
This happens when the trigger is querying or modifying a "mutating table", which is either the table whose modification activated the trigger, or a table that might need to be updated because of a foreign key constraint with a CASCADE policy.
However, a procedure is executed explicitly from another block via a procedure call, while a trigger is executed implicitly whenever the triggering event happens.
The triggering event is either a INSERT, DELETE, or UPDATE command. The trigger can be either row-level or statement-level, where the former fires once for each row affected by the triggering statement and the latter fires once for the whole statement.
be done, but I wanted to demonstrate that you need to take extreme care, because you can get some problems you might not have forseen.
If you choose to allow primary key updates, then you’ve pretty much got two options: 1) "simple update" The incoming SQL is say: where the column list includes the primary keys…