What is a paradigm?
In short, database design has a great relationship with the storage performance of data and the operation of data by developers. Therefore, the establishment of a scientific and standardized database needs to meet some specifications to optimize data and data storage methods. In RDBMS, these specifications can be called normal forms.
What are the three paradigms?
The first normal form: to ensure that each column maintains atomicity (fields cannot be divided), abbreviation: atoms cannot be divided
Each table has a primary key, (the primary key is a unique identifier )
Second paradigm: ensure that each column in the table is related to the primary key
Primary key columns and non-primary key columns follow a complete functional dependency (fully dependent)
The second paradigm is established on the basis of the first paradigm, that is, to satisfy the second paradigm, the first paradigm must be satisfied first
Third Normal Form: Ensure that each column is directly related to the primary key column
Meet the second normal form , but eliminate the transitive dependency
What is the relationship between the three paradigms?
The relationship between inclusion and satisfaction starts from the first paradigm, and every subsequent paradigm is established on the basis of satisfying the former
At last
The three paradigms are just the basic concepts of general database design, and a database with less redundancy and a reasonable structure can be established. If there are special circumstances, of course they must be treated specially. The most important thing in database design is to look at demand and performance, demand>performance>table structure. So you can't blindly pursue the paradigm to build a database.