Practical SQL Handbook, The: Using SQL Variants, Fourth Edition

Data Modification Through Views

Changing data through views is a thorny issue. The general problem, as we'll demonstrate here, is that commands to change data in a view sometimes can't be understood by SQL in an unambiguous way. Such updates are disallowed by every version of SQL. In other words, some views are inherently and logically not updatable.

There are other views that are logically updatable but that many versions of SQL rule nonupdatable. Disallowing a wide range of data modification statements makes for more severe restrictions but simplifies the rules about what you can and cannot do. Other SQL implementations go to great lengths to let you make as many kinds of changes as possible, in spite of the complications inevitably introduced ...