Can we set the primary key for item_master

If any body now plz ans me it's urgent

One user name store and another user name ramesh in same database, I have table name Item_master in Store user where as child table in ramesh user, Can we set the primary key for in two diffrent user, item_master in store user and child table for frogein key in ramesh user? If yes How?

i think u r asking whether we can create the primary key on the table and make it foreign for other.
if this is case then yes u can make easily.

alter table table1 add constraint constraint_name primary_key(columkn_name);

alter table table1 add constarint constraint_name foreign_key(col_name) referenced by table2;

pls check once syntax

reeta