DBMS

Which of the following conditions must be fulfilled to ensure the entity integrity constraint?

$4.$ Primany keys cannot have null values in any record.

$2.$ There should be no duplicate records in the table.

$3.$ Primary keys on every instance of an entity must be unique.

$4.$ INSERT and UPDATE operations resulting in an invalid primary key must not be allowed.

Pick ONE option

$1,2$ and $4$

$1,3$ and $4$

All of these

Clear Selection