Hi all,

I want to protect the result of a query. That means every database
update which change the result of the quer must be discovered.

For example:
the query is
SELECT name
FROM emp
WHERE age > 50
When the connection is closed. And another app execute
INSERT INTO emp (name, age) values ("asd", 60)
Some warning must be issued.

In this simple case, we can write a trigger to solve it. However, in
some other cases, the query is much complex (e.g there is sub-query).
How to write the trigger efficiently? Is there any research topic
about this area? (if yes, would you pls suggest me some keywords).

Thank in advance
AgileBall