n} relationship, a customer is required to have at least one account and one address.
n} 关系，一个客户需要拥有至少一个帐户和一个地址。
2
N cardinality (account, address).
n关系(帐户、地址)。
3
With the N-Tier improvements for Entity Framework, we want to address some of the same problem space as DataSet, but we want to avoid the primary issues with it.