posted 21 years ago
That is a view on one table - which you can update. However in SQL there are a whole bunch of restrictions on views if you want to be able to update the data. For example you cannot update a normal view which includes: GROUP functions, a GROUP BY clause, DISTINCT, subquery, DISTINCT, joins accross multiple tables etc.
In Oracle, you can write an updatable materialized view or a writable materialized view if you have configured Oracle to use advanced replication.