Free sampleIdentify Considerations for Relational Data on Azureeasy
In a relational database, how is a single instance of a real-world entity such as one customer represented?
- AAs one row within the table that models that entity Correct
- BAs one column within the table that models that entity
- CAs a separate table created for that individual instance
- DAs a datatype definition applied to the whole table
A row is one instance of an entity; the table is the whole collection of those instances. A relational table contains rows where each row represents a single instance of an entity, so one customer occupies one row in the customer table.
Why A is correct: Correct. A relational table contains rows where each row represents a single instance of an entity, so one customer occupies one row in the customer table.
Why B is wrong: A column stores one attribute (such as Email) across many entity instances, not a single instance.
Why C is wrong: A table models a whole collection of entities; one instance is a row inside it, not its own table.
Why D is wrong: A datatype constrains the values a column may hold; it does not represent an entity instance.