Shulou(Shulou.com)06/01 Report--

This article is about what the three levels of abstraction are in data abstraction. The editor thought it was very practical, so I shared it with you as a reference. Let's follow the editor and have a look.

There are three levels of data abstraction in a database: physical level, logical level, and view level.

This article introduces the data abstraction of the database to let you understand what the data abstraction is and the composition system of the data abstraction. I hope it will be helpful to you. [video tutorial recommendation: MySQL tutorial]

What is data abstraction?

The database system is composed of complex data structures. in order to simplify the interaction between the user and the database, the internal irrelevant details will be hidden from the user. This process of hiding irrelevant details from users is called data abstraction.

Data abstraction architecture

There are three levels of abstraction in data abstraction, which are:

1. Physical level

The physical level is the lowest level of data abstraction, which describes how the data is actually stored in the database; we can get complex data structure details at this level.

Example: suppose we store student information in the student table

At the physical level, these records can be described as memory blocks (bytes, gigabytes, terabytes, etc.). However, these details are usually hidden from programmers, and in general, we cannot feel them intuitively; this is mainly provided to database vendors to study.

2. Logical level

The logical level is the intermediate level of the three-level data abstraction architecture, which describes the data stored in the database, such as what data is stored and the relationship between the stored data.

Example: or an example of storing student information in a student table

At the logical level, these records can be described as fields and properties and their data types, and the relationship between them can be logically implemented. This is mainly considered by programmers or database administrators, and programmers usually work at this level, setting the structure of data tables and various data types.

3. View level

The view level is the highest level of data abstraction, which describes the interaction between the user and the database system, and the user view interface can add, delete, modify, query and other operations.

Example: or an example of storing student information in a student table

At the view level, users only need to interact with the system through the user graphical interface (GUI) and enter details on the screen. They do not know how the data is stored or the details of the data stored; these details are hidden from them.

The user does not need to know the details of the database schema, such as data structure, table definition, etc.; the user only needs to know the data that is fetched from the database and returned to the view level.

Thank you for reading! On the data abstraction there are three levels of abstraction what is shared here, I hope the above content can be of some help to you, so that you can learn more knowledge. If you think the article is good, you can share it and let more people see it.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.