通常，选项a是更好的方法.

Generally, option a, is the better approach.

这使您可以轻松地一次请求一个帐户的所有交易.对于每笔交易，都不需要其他查找.

This allows you to easily request all the transactions for an account at once. No additional lookup is needed, for each transaction.

在某些情况下，选项b可能适用，例如对所有事务频繁运行的查询.

There are use cases where option b may be appropriate, such as frequently running queries on all of the transactions.