Basic principles of database design: 1. Store data with the same theme in a data table; 2. Try to eliminate redundancy and improve the speed of database access; 3. When designing the data table structure, you should Consider the dynamic adaptability of the table structure.
Basic principles of database design:
(1) Store data with the same subject in one database In the table, "one table, one use".
(2) Try to eliminate redundancy and increase the speed of accessing the database.
(3) It is generally required that the database design reaches the third paradigm, many-to-many, which eliminates data redundancy, modification exceptions, insertion exceptions, and deletion exceptions to the greatest extent, and basically meets the requirements of relationship standardization.
(4) In a relational database, the relationship between each data table can only be one-to-one and one-to-many. Many-to-many relationships must be converted into one-to-many relationships for processing.
(5) When designing the data table structure, the dynamic adaptability of the table structure should be considered.
The main steps of database design:
1. Requirements analysis: Understand the user’s data needs, processing needs, security and integrity requirements;
2. Conceptual design: design the system conceptual model through data abstraction, usually an E-R model;
3. Logical structure design: design the schema and external schema of the system, for the relational model it is mainly basic tables and views;
4. Physical structure design: design the storage structure and access method of data, such as index design;
5. System implementation: organize data storage, compile application programs, and test run;
6. Operation and maintenance: The system is put into operation and long-term maintenance work is required.
Related learning recommendations: SQL video tutorial, mysql video tutorial
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