CODEWITHSUNDEEP
databasedatabase-designentityrelational-databaseentity-relationship
AkshaiShah
AkshaiShah

Reputation: 5939

Convert from ER to Relational Database - Mapping Weak entity types

I am trying to map the weak entity CatalogueEntry into a relational schema, and I am unsure which of the entities are the owner of this weak entity type. So, I don't know what the primary key of the relation in the relational schema is.

Anyone have any ideas? I have added an image below, thanks.

enter image description here

Upvotes: 0

Views: 4111

Answers (2)

Walter Mitty
Walter Mitty

Reputation: 18940

What is a Catalogue? Why doesn't catalogue appear on the diagram?

Sorry to ask stupid questions, but you learn to do that when you do data analysis.

It's useful to understand the data pretty well at the conceptal (ER) level, before switching to the relational level.

Upvotes: 1

Ahmed Tanvir
Ahmed Tanvir

Reputation: 197

From the figure it shows that the weak entity CatelogueEntry depends on the Album strong entity by an identifying relationship (HasEntry). For each catelogueEntry there must be an albumid. So here there are two tables. One is for Album and another table is for catelogueEntry. The catelogueEntry must contain a foreign key from album entry.

Upvotes: 0

Related Questions