📅  最后修改于: 2022-03-11 14:56:52.934000             🧑  作者: Mango
Entity-
An entity is an object that exists. It doesn't have to do anything;
it just has to exist. In database administration,
an entity can be a single thing, person, place, or object.
Data can be stored about such entities.
A design tool that allows database administrators to view the relationships
between several entities is called the entity relationship diagram (ERD).