The Relational Data Model
4 important questions on The Relational Data Model
What is data integrity enforced by?
- Using null for missing data
- Specified domains for attributes
- Entity integrity
- Referential integrity
- Enterprise constraints
How do you ensure entity integrity?
- Specify a primary key
- No attribute of a primary key can be null
- Tables for weak entities should inherit (part of) their primary key from their parent tables
How do you ensure referential integrity?
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What are enterprise constraints?
e.g. only 20 staff allowed at one branch. DBMS must enforce this rule
The question on the page originate from the summary of the following study material:
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