referential constraints in which the column CNO of table CUSTOMER is the referenced column
SELECT owner, tablename, columnname, fkeyname, rule
FROM DOMAIN.FOREIGNKEYCOLUMNS
WHERE reftablename = 'CUSTOMER'
AND refcolumnname = 'CNO'
All referential constraints in which the column HNO of table RESERVATION is the referenced column
SELECT fkeyname, rule
FROM DOMAIN.FOREIGNKEYCOLUMNS
WHERE tablename = 'RESERVATION'
AND columnname = 'HNO'
All referential constraints in which the referenced columns come from table RESERVATION
SELECT DISTINCT fkeyname, rule, refowner, reftablename
FROM DOMAIN.FOREIGNKEYCOLUMNS
WHERE tablename = 'RESERVATION'