问题
While doing a homework for a class I suddenly found myself stumped by a sentence:
The work must also contain at least 4 additional entities(not tables) with meaningful data.
I had to create an example database for a museum, for cataloging various pieces, assigning themes to them, and creating expositions by themes. Each of these tables already must have 10 entries, so I am quite confused what could be asked by the 4 additional entities..
Help?
回答1:
In my experience the two have always been synonymous (entity and table). I've heard people refer to the data as an entity before but normally entity is referring to the table. My experience is mostly with SQL server and Microsoft Dynamics CRM. What platform are you working in?
An entity set usually represents a slice of an entities data, i.e. all contacts who live in the bay area would be an entity set of the contact entity.
Attributes belong to an entity and describe the columns of the entity. I've always heard the entity-attribute and table-column nomenclatures used together but have yet to see a difference between the two.
来源：https://stackoverflow.com/questions/6162746/what-is-the-difference-between-an-entity-entity-set-and-attributes