Differences between "identifying" and "non identifying relationship"


I started using the Workbench and was doing a database model, but those two relationships appear in the tables, what is the difference?


"non identifying relationship":

asked by CesarG 05.06.2017 в 21:34

1 answer


A identifying relationship is used to make sense of a weak entity . A weak entity can not be unequivocally identified with its attributes, so it needs another entity that acts as an identifier.

For example: We have an entity Building , and another Dispatch

The office is identified by its number and its floor. However, we can not identify it completely without knowing what building it belongs to. Therefore, we need an identifying relationship, in which Building acts as an identifier and the plant and the dispatch number act as discriminants. If we gather this information you can unequivocally identify any office.

answered by 14.06.2017 в 19:53