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 uniqueness (no duplicate values in the specified column) and prohibits null values (acting as a NOT NULL constraint). Unique constraints allow nulls, and Check or Not Null constraints do not enforce uniqueness alone.