ALTER TABLE cust_main CHANGE ss ss char(11) NULL; ALTER TABLE cust_main CHANGE day daytime varchar(20) NULL; ALTER TABLE svc_acct CHANGE password _password varchar(25) NOT NULL; ALTER TABLE part_svc CHANGE svc_acct__password svc_acct___password varchar(25) NULL; ALTER TABLE part_svc CHANGE svc_acct__password_flag svc_acct___password_flag char(1) NULL; ALTER TABLE agent_type CHANGE type atype varchar(80) NOT NULL;