MYSQL database design and database design example (2) _ MySQL

MYSQL database design and database design example (2) bitsCN.com database design-requirement analysis

1> The main task or function of requirement analysis is to investigate in detail the objects to be processed in the real world, understand the general working situation of computer systems, and clarify the various requirements of users, then, based on this, determine the functions of the new system,

We also need to consider possible system expansion and changes in the future.

2> in the investigation process, the focus is "data" and "processing", which are collected and analyzed through investigation to obtain users' requirements for the database.

These requirements generally include a. information requirements. The user needs to obtain the content and nature of the information from the database.

B. handling requirements. What kind of processing functions should a user complete, what requirements should be made for the processing response time, and how should they be processed? batch processing and on-line processing are generally included.

C. security and integrity requirements

3> Data Dictionary

Data Dictionary is a collection of various types of data descriptions in the system. it is the main result of detailed data collection and data analysis. It plays an important role in a database design.

Data dictionaries generally include data results of data items, data streams, data storage, and processing processes.

A data item is the smallest component point. multiple data items constitute a data structure. the data dictionary defines data items and data structures to describe the logical content of data streams and data storage.

(1) data items: data items are inseparable data units.

(2) data structure: the data structure reflects the combination of individual data. it may consist of several data items or several data structures, it can also be composed of several data items and data structures.

(3) Data Stream: data stream is the path for data transmission in the system.

(4) data storage: Data storage is the place where the data structure stays or is stored, and also the source and destination of the data stream.

(5) processing process: the specific processing logic is generally described by the number of judgments or the decision table.

A data dictionary describes the metadata of data in a database, rather than the data itself.

Data dictionaries are established in the demand analysis stage and are constantly modified, enriched, and improved during the database design process.

Write a http://www.cnblogs.com/haoke/archive/2012/12/11/2813537.html

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