What does pk primary key mean?

PK has many meanings, but it has different meanings in the computer database. It corresponds to the primary key of the table. Please join me to find out more below.

PK (primary key) represents the primary key in the database and is the only primary attribute column of a table.

In the second normal form 2NF of database design, it is required that each instance or row in the database table must be uniquely distinguishable, so PK is generated.

For example, a student table student has the following attributes: id, name, sex, address. The id can be used as the PK of the student table, and

PK is non-repeatable.

In the student table, PK can be set to increase from 1, 2, 3...n. The rest of the name, sex, and address can be repeated.

In addition, PK can also be used for table linking to remove the Cartesian product.

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