The NOT NULL attribute of column Credit_Line in table ACCOUNT has to be dropped because some other account types have been added that do not have a credit line.
ACCOUNT 表中的 Credit_Line 列的 NOT NULL 属性必须删除，这是因为添加了没有信用行的其他账号类型。
2
Figure 2 shows the two systems, the loan submission and the credit bureau system, and the interactions we'll focus on for the remainder of this column.
图2显示了两个系统、贷款提交和商业资信咨询机构系统以及我们将在这个专栏的余下部分着重讨论的交互。
3
In the last column in the UML workbook series, we devised a system that would interact with both a human actor (a loan applicant) and an external system actor (a credit bureau).