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This article will explain in detail what is the use of the competition key for you. 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.

Competition has many meanings, but it has a different meaning in the computer database. He corresponds to the primary key (primary key) of the table.

Primary key represents the primary key in the database and is the only primary attribute column of a table.

In the second normal form of database design, 2NF requires that each instance or row in the database table must be uniquely localized, so there is competition.

For example, a student table student has the following attributes id,name,sex,address. Among them, id can be used as the competition of the student table.

Competition is unrepeatable.

The competition in the student table can be set to increment from 1pm 2pm 3.n. The rest of the name,sex,address can be repeated.

In addition, competition can also be used for table links to remove Cartesian products.

What is the use of the competitive primary key to share here, I hope that the above content can be of some help to you, can learn more knowledge. If you think the article is good, you can share it for more people to see.

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