ALTER TABLE NATION ADD FOREIGN KEY (N_REGIONKEY) REFERENCES REGION(R_REGIONKEY);
 ALTER TABLE SUPPLIER ADD FOREIGN KEY (S_NATIONKEY) REFERENCES NATION(N_NATIONKEY);
 ALTER TABLE CUSTOMER ADD FOREIGN KEY (C_NATIONKEY) REFERENCES NATION(N_NATIONKEY);
 ALTER TABLE PARTSUPP ADD FOREIGN KEY (PS_SUPPKEY) REFERENCES SUPPLIER(S_SUPPKEY); ALTER TABLE PARTSUPP ADD FOREIGN KEY (PS_PARTKEY) REFERENCES PART(P_PARTKEY);
 ALTER TABLE ORDERS ADD FOREIGN KEY (O_CUSTKEY) REFERENCES CUSTOMER(C_CUSTKEY);
 ALTER TABLE LINEITEM ADD FOREIGN KEY (L_ORDERKEY) REFERENCES ORDERS(O_ORDERKEY); ALTER TABLE LINEITEM ADD FOREIGN KEY (L_PARTKEY,L_SUPPKEY) REFERENCES PARTSUPP(PS_PARTKEY,PS_SUPPKEY);