inheritance ...

    I've the folowing problem :

I've create a table cities :

create table cities (name varchar(20) , population int4) ;

I've also create a table capitals with inheritance :

create table capitals (country varchar(20) ) inherits (cities) ;

But when i want to add a column to cities , the column is not added to capitals : this is not a object approach ! Isn't it ? How can i do ?
 

                                                                                Thanks for the response

                                                                                                                        Loic

P.S : one time , i've add a column to the table cities and i had the result ADD but i couldn't see the column added ! Have you ever heard about this ?