Question:
What is a primary key in a relational database?
What is a primary key in a relational database?
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Choose primary keys that are simple, unique, and unlikely to change (e.g., IDs).
Updated On: Jun 18, 2025
- A unique identifier for each record in a table
- A key used for sorting records
- A key linking two tables
- A key for encrypting data
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The Correct Option is A
Solution and Explanation
A primary key in a relational database:
- Uniquely identifies each record in a table.
- Ensures no duplicate or null values.
- Often used for referencing in other tables (foreign keys).
Option (2) relates to indexing, (3) to foreign keys, and (4) to security, none of which define a primary key.
Option (1) is correct.
- Uniquely identifies each record in a table.
- Ensures no duplicate or null values.
- Often used for referencing in other tables (foreign keys).
Option (2) relates to indexing, (3) to foreign keys, and (4) to security, none of which define a primary key.
Option (1) is correct.
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