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This article mainly introduces "what is the three paradigms of DB". In the daily operation, I believe that many people have doubts about what the three paradigms of DB are. The editor consulted all kinds of materials and sorted out simple and easy-to-use operation methods. I hope it will be helpful to answer the questions of "what are the three paradigms of DB?" Next, please follow the editor to study!

Three paradigms of database:

The first normal form (1NF) concept: the fields in the database table are of a single attribute and cannot be further divided. That is, the atomic constraint on the attribute. Description: the types of single attributes include integer type, character type, logical type, date type, etc. Note: collections, arrays and other types do not belong to the type of a single attribute. The premise of the second normal form (2NF): the premise of satisfying the second paradigm is to satisfy the first paradigm first. Concept: non-primary attributes must be completely dependent on the primary key. That is, the uniqueness constraint on the record. Description: the primary key may be composed of multiple attributes, and complete dependence means that there is no non-primary attribute that depends on a part of the primary key. The premise of the third normal form (3NF): the premise of satisfying the third paradigm is to satisfy the second paradigm first. Concept: any non-primary attribute does not depend on other non-primary attributes, otherwise there will be data redundancy. That is, a constraint on field redundancy. Explanation: both the second paradigm and the third paradigm are talking about the dependence of non-primary attributes on other attributes: the key of the second paradigm is whether the non-primary attributes are completely dependent on the principal attributes. The key of the third paradigm is whether the non-primary attribute directly depends on the primary attribute or on other non-primary attributes. At this point, the study of "what is the three paradigms of DB" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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