All Questions
Tagged with erd primary-key
5 questions
0
votes
1
answer
250
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Should I Use a Composite Key or a Single-Column Primary Key in my Entity Relationship Diagram?
I am designing an Entity Relationship Diagram (ERD) for a database that includes a table with variants annotated by different tools. In this table, each variant is annotated by a specific tool, and ...
- 101
3
votes
1
answer
870
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If an entity's primary key must contain a foreign key, does that make the entity weak?
I'm currently learning about strong and weak entity types in the context of RDBMS. While reading, I came across this statement:
"A weak entity is dependent on a strong entity to ensure its ...
- 141
0
votes
2
answers
89
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Multiple Primary-Foreign Key connections between Tables Redundant?
I have two tables, Reviews and Critic
I'm pretty new to RDBMS and I was wondering if the connection between Review.rID and Critic.Review is redundant?
My reasoning is that a single critic can have ...
1
vote
1
answer
2k
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Clarification on Cardinality and Participation
I'm currently redesigning a schema with 20 or so tables and my first task is to create an ERD from the existing tables/constraints/relationships. This has proven more difficult than I expected because ...
- 121
2
votes
2
answers
688
views
Composite primary key plus a separate (surrogate) id column for foreign key references
I am trying to build a database about locations like so:
Country → Region → Town
Countries will be populated with a list of pre-defined worldwide countries, regions & towns are input by users.
...
- 123