ERD: Associative Entities

[@mrd9421]

Thanks for sharing! You really saved the day!😃👍

[@coffeeemore]

This is wayyyyyy better than my professor taught in class. Thank you so much.

[@edmundyeung3157]

so true

[@kartikkumar-xh1if]

great video 👍

[@zuoyizhang2263]

Super Clear! Thank you!

[@leahfeldman244]

Why do I put the mandatory ones on the other sides of the associative entities?

[@DustinOrmond]

In general, this will be the case, so I tell my students to do it this way. In reality, however, it will be an optional-one if two conditions are met (1) the foreign key in the associative entity can have null (or blank) values and (2) the foreign key is not part of the primary key because being part of the primary key it can't be null.

[@GamanToad]

Hi, if my tenary relationship is 1:M:N would i add the primary key of the entity on the 1 side as a foreign key in the table of the associative entity (as opposed to part of it's composite primary key)

[@DustinOrmond]

If you have a ternary relationship, you need to consider everything as if it was a many-to-many-to-many relationship. So, yes, you would either have all the foreign keys make up the primary key or you need to create a surrogate primary key.

[@firomsamt7642]

hello sir thank you for the video what book did you use as a reference

[@patriciagerges]

gold

[@innocentboi561]

thanks :>