SQL Reference Contents
create view - construct a virtual class
create view view_name
as
select expression1 [as attr_name1]
{, expression_i [as attr_namei]}
[from from.last]
[where qual]
create view will define
a view of a class. This view is not physically materialized; instead the
rule system is used to support view processing as in [STON90]. Specifically,
a query rewrite retrieve rule is automatically generated to support retrieve
operations on views. Then, the user can add as many update rules as desired
to specify the processing of update operations to views. See [STON90]
for a detailed discussion of this point.
--
--create a view consisting
of toy department employees
--
create view toyemp as
select e.name
from emp e
where e.dept = 'toy'
--
--Specify deletion semantics for toyemp
--
create rule example1 as
on delete to toyemp
do instead delete emp
where emp.oid = current.oid
create table(l)
, create rule(l)
,
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