Multiple choice technology databases

You need to enforce these two business rules: 1. No two rows of a table can have duplicate values in the specified column. 2. A column cannot contain null values. Which type of constraint ensure that both of the above rules are true ?

  1. Check

  2. Unique

  3. Not Null

  4. Primary Key

  5. Foreign Key
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A Primary Key constraint enforces both uniqueness (no duplicate values) and the NOT NULL constraint (no null values). This makes it the only single constraint type that guarantees both business rules are satisfied simultaneously for a table column.

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