The meaning of entity essence, concrete things, individual subject, phenomenon supporter, etc. , generally refers to things that can exist independently, as the basis of all attributes and the origin of all things.

Basic introduction

English substance, a word derived from Latin substance, has the meaning of essence, concrete things, individual subjects, supporters of phenomena and so on.

An important philosophical concept initiated by Aristotle, an ancient Greek philosopher, is also an important philosophical category used by many philosophers in the history of western philosophy. Also translated into individual ontology. Its meaning generally refers to things that can exist independently, as the basis of all attributes and the origin of all things.

Basic feelings:

Entity refers to objects or things that exist objectively in the real world and can be distinguished from each other. As far as a database is concerned, an entity usually refers to a collection of something. It can be concrete people and things, or it can be abstract concepts and connections.

Entity contact diagram is a practical tool to describe the conceptual world and establish conceptual model. The design process of database is to describe the organization mode with E-R diagram, and then further transform it into any data model supported by DBMS. The three elements of E-R diagram are entity, attribute and connection, which are represented by rectangular box, elliptical box and diamond box respectively. ?