Ora-2270 Error while adding foreign key constraint on top a view

Question

While adding a constraint, referencing a foreign key column from a view raises error. However, it works fine over a table.
Here's the sample script:
create table t_temp (
sample_id number,
text varchar2(40))
alter table t_temp add constraint temp_pk
primary key (sample_id);
create view tempvw as select sample_id,text from t_temp;
create table t_sample (
uniq_id number,
sample_id number,
sample_text varchar(40));
=========
ALTER TABLE t_sample ADD CONSTRAINT FK_sample_temp
     FOREIGN KEY (sample_id) REFERENCES t_temp (sample_id);
This works fine.
=========
==============
The following raises ERROR....
ALTER TABLE t_sample ADD CONSTRAINT FK_sample_temp1
     FOREIGN KEY (sample_id) REFERENCES tempvw (sample_id);
Error starting at line 1 in command:
ALTER TABLE t_sample ADD CONSTRAINT FK_sample_temp1
     FOREIGN KEY (sample_id) REFERENCES tempvw (sample_id)
Error report:
SQL Error: ORA-02270: no matching unique or primary key for this column-list
02270. 00000 - "no matching unique or primary key for this column-list"
*Cause:    A REFERENCES clause in a CREATE/ALTER TABLE statement
gives a column-list for which there is no matching unique or primary
key constraint in the referenced table.
*Action:   Find the correct column names using the ALL_CONS_COLUMNS
catalog view

Answer 1

What exactly are you trying to accomplish by having a
referential integrity constraint on a view (which is
not allowed). PKs and FKs are allowed on views. DISABLE NOVALIDATE is the only allowed state for them. View constraints are used for query rewriting: http://download.oracle.com/docs/cd/B19306_01/server.102/b14223/qradv.htm#sthref1457
Regards,
Dima