Cascade constraint gone!!!

Hi,

I recently wipe my database away.  And some of the tables have a UPDATE
CASCADE on it to another table.  
When I reload the data from my backup that I did with pg_dumpall.  My
code started to give me an error because I tried to modify a table that
was reference from another table.  But the referenced table should have
an UPDATE CASCADE.  But according to the error it doesn't. 

Is there a way to add the ON UPDATE CASCADE back without dropping any
table again?

Thanks


-- 
Linh Luong