Which constraint can be used to ensure that identical values are never stored in a set of columns in a table?
Which constraint can be used to ensure that identical values are never stored in a set of columns in a table?
A primary key constraint ensures that each value in the column or set of columns is unique and that no null values are allowed. This constraint is designed specifically to prevent duplicate values, making it the appropriate answer for ensuring that identical values are never stored in a set of columns in a table.
C is good : C. Primary key