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。

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Figure 11 shows an assign transform that sets the prefix attribute of Person to null.

图11显示了一个赋值转换，它将Person的prefix属性设置为空。

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This tag determines whether or not the field in the name attribute is null.

这个标签确定name属性中的字段是否为空。

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