The purpose of the ____ constraint is to ensure that two records do not have the same value stored in the same column.However,it can contain NULL values.
A) PRIMARY KEY
B) UNIQUE
C) CHECK
D) FOREIGN KEY

Question

The purpose of the ____ constraint is to ensure that two records do not have the same value stored in the same column.However,it can contain NULL values.​
A) ​PRIMARY KEY
B) ​UNIQUE
C) ​CHECK
D) ​FOREIGN KEY

Quizplus · Accepted Answer

The UNIQUE constraint ensures that two records do not have the same value stored in the same column, but it can contain NULL values. The PRIMARY KEY constraint also ensures uniqueness, but it cannot contain NULL values. The CHECK constraint is used to enforce domain integrity, and the FOREIGN KEY constraint is used to establish a link between two tables.

The Purpose of the ____ Constraint Is to Ensure That