A.添加一個UniqueConstraint對象到CurrentOrders中
B.添加一個ForeignKeyConstraint對象到CurrentOrders中
C.添加一個DataRelation對象到CurrentOrders中,并且設(shè)置ChildKeyConstraint的屬性為指向theappropriate行
D.添加一個DataRelation對象到CurrentOrders中,并且設(shè)置ParentKeyConstraint的屬性為指向適當(dāng)?shù)男?/p>