Even still, with physical data models you can reverse engineer from the actual database or from the data definition language (DDL) file.
还可以对实际数据库或数据定义语言(DDL)文件进行反向工程，生成物理数据模型。
You will use it when you convert the extracted data in the database to the new masked data with the masking definition that is contained in this file.
当您在将数据库中的提取数据转化为新的屏蔽数据时，您将会用到它。
A new Crystal Report will then be created without actually connecting to any database, because this Crystal Report will be based on a data definition file.
不需要连接到任何数据库，就可以建立一个新的Crystal Report，因为这个Crystal Report是基于一个数据定义文件的。
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