7 NESMA 识别 FPA-TABLES 案例研究NESMA 识别 FPA-TABLES 案例研究

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概述

NESMA 识别 FPA-TABLES 案例研究

Problem description

For a sales system that records and supports sales activities, the following entity types have been defined as part of a data model in third normal-form:
对于记录和支持销售活动的销售系统，以下实体类型已定义为第三范式数据模型的一部分：

Product:

product number (consists of: product group number, sequence number)
description
country of origin (code)
buyer number
price
VAT code

Country:

country code
name of country

VAT Rate:

VAT code
VAT rate
effective date

Buyer:

buyer number
buyer name

Functions are available for each of the entity types in order to add, change, delete, and query data. Additionally, a report with all the occurrences or specimens of data can be printed for each entity type.
功能可用于每种实体类型，以添加、更改、删除和查询数据。此外，可以为每个实体类型打印包含所有数据的报告。
Should these files be considered internal logical files? And is an FPA tables ILF or an FPA tables ELF present here? If so, what is its complexity?
这些文件是否应被视为内部逻辑文件？这里是FPA表格ILF还是FPA表格ELF？如果是这样，其复杂性是什么？

Discussion

Within the framework of section 4.20, the entity type VAT Rate is not an FPA table, but an individual internal logical file. Product is also an individual internal logical file.
在第4.20节的框架内，实体类型增值税税率不是FPA表，而是单个内部逻辑文件。产品也是一个单独的内部逻辑文件。

Because the entity types Country and Buyer are used only for decoding the codes and numbers used (i.e., they fulfill a secondary function), they should be considered an FPA table. No additional information, for example, is maintained about the buyers.
由于实体类型Country和Buyer仅用于解码所使用的代码和数字（即，它们实现了辅助功能），因此应将其视为FPA表。说明，没有针对实体的维护。

There is an FPA tables ILF because all the entity types can be maintained. Its complexity is determined as follows: The total number of entity types (two: Country and Buyer) determines the number of record types of the FPA tables ILF. The total number of data element types (four in all) of the different entity types of the FPA table type makes up the number of data element types of the FPA tables ILF. Via the complexity matrix for internal logical files, the complexity of the FPA tables ILF can be determined (low)
有一个FPA表ILF，因为所有实体类型都可以维护。其复杂性确定如下：实体类型的总数（两个：国家和买方）决定了FPA表ILF的记录类型的数量。FPA表不同实体类型的数据元素类型总数（共四种）构成了FPA表格ILF的数据元素类型数量。通过内部逻辑文件的复杂度矩阵，可以确定FPA表ILF的复杂度（低）

Count one external input, one external output, and one external inquiry for the FPA tables ILF, regardless of the number of entity types of which the FPA tables ILF consist.
统计FPA表ILF的一个外部输入、一个外部输出和一个外部查询，无论FPA表ILF包含的实体类型的数量如何。

Solution

Count three internal logical files:

Product: consists of one record type and seven data element types. The complexity is therefore low.
VAT Rate: consists of one record type and three data element types, so that the complexity is low.
One internal logical file for the FPA tables. There are four data element types (country code, name of country, buyer number, buyer name) and two record types (the entity types Country and Buyer). Complexity is therefore low.

计算三个内部逻辑文件：
-产品：由一种记录类型和七种数据元素类型组成。因此，复杂性较低。
-增值税税率：由一种记录类型和三种数据元素类型组成，因此复杂性较低。
-FPA表的一个内部逻辑文件。有四种数据元素类型（国家代码、国家名称、买方编号、买方名称）和两种记录类型（实体类型国家和买方）。因此，复杂性较低。

原文 NESMA官方示例第7章 FPA TABLE