inheritance and update

Is it possible to update rows in a derived class via the base class ?

I have a base class, let's say BASE and two derived tables DERIVED1 and DERIVED2.

Suppose that select * from DERIVED1; returns :
id | name
1 | joe
and select * from DERIVED2; returns :
id | name
2 | bill
So select * from BASE*; returns as expected
id | name
1 | joe
2 | bill

But I can't update the tables using the following query :
update BASE* set name='john' where id=1;

Is there another means to do such an update ?

Thank you for any answer.

Francois

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Francois TETE
StreamCORE
2 place des Hauts Tilliers - 92632 Gennevilliers Cedex - France
Mail : francois(dot)tete(at)stream-core(dot)com
Phone: +33 1 41 21 46 22
Fax : +33 1 41 21 46 27