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This article will explain in detail what are the characteristics of the data model. The editor thinks it is very practical, so I share it for you as a reference. I hope you can get something after reading this article.

The characteristics of the data model are: 1, conceptual data model, user-oriented and real-world-oriented data model; 2, logical data model, which directly reflects the needs of business departments; 3. Physical data model, it has the characteristics of intuitive expression of cognitive objects in the form of physical objects or drawings.

The operating environment of this tutorial: windows7 system, Dell G3 computer.

According to different application levels, data models are divided into conceptual data model, logical data model and physical data model.

1. Conceptual data model

It is characterized by a user-oriented and real-world-oriented data model, which describes the conceptual structure of a unit, and has strong semantic expression ability, which can express all kinds of semantic knowledge in the application conveniently and directly. it is simple, clear and easy for users to understand; the conceptual model is a subjective artifact.

2. Logical data model

The characteristic is that it directly reflects the needs of the business department and plays an important role in guiding the physical implementation of the system; the data blueprint of the enterprise can be drawn through entities and relationships; and the logical model provides a mechanism for user-defined integrity constraints. to reflect the specific semantic constraints that the data involved in a specific application must comply with.

3. Physical data model

It is characterized by the intuitive expression of cognitive objects in the form of physical objects or drawings; each logical data model has its corresponding physical data model when implemented; describing the organizational structure of data on the storage medium is not only related to the specific DBMS, but also related to the operating system and hardware.

Extended data:

Data model structure is mainly divided into data structure, data operation and data constraint.

The main contents are as follows: 1. Data structure mainly describes the type, content, nature and relationship of data. Data types, such as records in DBTG mesh model, data items, relationships in relational models, and so on. Data structure is the basis of data model, and different data structures have different operations and constraints.

2. Data operation mainly describes the operation type and operation mode on the corresponding data structure. Is a collection of operation operators, including several operations and inference rules, to operate on a database composed of valid instances of the target type.

3. Data constraints mainly describe the syntax, semantic relations, constraints and dependencies between them, as well as the rules of dynamic changes of data in the data structure, in order to ensure the correctness, effectiveness and compatibility of the data. According to different principles, constraints can be divided into data value constraints and data connection constraints; static constraints and dynamic constraints; entity constraints and reference constraints between entities.

This is the end of the article on "what are the characteristics of the data model". 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, please share it for more people to see.

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