text: alter table warehouse add constraint pk_warehouse 
    primary key (w_id);  
  
  alter table district add constraint pk_district 
    primary key (d_w_id, d_id);
  
  alter table customer add constraint pk_customer 
    primary key (c_w_id, c_d_id, c_id);
  
  create index ndx_customer_name 
    on customer (c_w_id, c_d_id, c_last, c_first);
  
  alter table oorder add constraint pk_oorder 
    primary key (o_w_id, o_d_id, o_id);
  
  create unique index ndx_oorder_carrier 
    on oorder (o_w_id, o_d_id, o_carrier_id, o_id);
  
  create unique index pk_0order 
    on oorder(o_w_id, o_d_id, o_c_id, o_id);
   
  alter table new_order add constraint pk_new_order 
    primary key (no_w_id, no_d_id, no_o_id);
  
  alter table order_line add constraint pk_order_line 
    primary key (ol_w_id, ol_d_id, ol_o_id, ol_number);
  
  alter table stock add constraint pk_stock
    primary key (s_w_id, s_i_id);
  
  alter table item add constraint pk_item
    primary key (i_id);
  