Vb.net data center Charging System Reconstruction-Summary (3) software engineering document 2

Source: Internet
Author: User

Vb.net data center Charging System Reconstruction-Summary (3) software engineering document 2

In the previous article, I wrote the requirement specification to add an IPO diagram. What is an IPO diagram? I have learned more about it.

An IPO refers to the Input, Processing, and Output of a variant structure in a structured design ). Is a detailed design tool for each module.

To put it bluntly, the IPO diagram is to describe the input and output data and data processing.

Here, the login is used as an example:

During login, the user name and password are entered. Processing: Check the username and password. Output main form. This is the IPO diagram of login.

In the requirement manual, you can also draw a simple Entity-relational diagram (Entity-Relationship). Because this diagram also exists in the Database Design Manual, we will not talk about it here.

The above is the software requirement document.

(3) Database Design Specifications

In the database design manual, the most important thing is not to write clearly the conventions for database naming, as shown in

The most important thing is the E-R diagram and the details of each table.

Here I use the yitu software.

In a true E-R diagram, there should be no many-to-many relationship, and a one-to-one relationship, such as between students and cards. As I mentioned before, some people think they must follow the three paradigm completely, however, for specific business analysis, data redundancy is allowed to improve query efficiency. In this system, you can merge the card table and student table to improve query efficiency. Therefore, the student entity and the card entity can be combined.

After drawing the E-R diagram, there are details of each entity, take the student entity as an Example

There is also a Data Relationship Diagram of database conversion.

Finally, each table is designed. Take the student table as an example.

List stored procedures used

The final content is data dictionary.

What is data dictionary?Data Dictionary defines and describes data items, data structures, data streams, data storage, processing logic, and external entities, the purpose is to give a detailed description of each element in the data flow chart.

It sounds like tianshu. There are only two points to sort out carefully.

1) the data dictionary stores the relevant information used by the database. It is a set of read-only tables for users.

2) Composition of data dictionaries:
1. Data items
2. Data Structure
3. Data Stream
4. Data Storage
5. handling process
Take my data dictionary as an example. only part of the data is truncated.

Then the description of the data item

In my Database Design Manual, the data dictionary mainly consists of these two parts. If you have any shortcomings, please point out them.

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