dynamic rules? - Mailing list pgsql-sql

Is it possible to create a select rule that returns results depending on a
where clause in the original select statement?

For Example (oversimplified):

CREATE TABLE one (data int);
CREATE TABLE two (data int);

I make the query:
SELECT data FROM number WHERE type=1;

If the type is 1 (type=1) I want to return 'SELECT data FROM one;'
If the type is 2 (type=2) I want to return 'SELECT data FROM two;'

Thanks,

Chris