Consider the following DBDL description of an entity: Teachers (teach_num: variable length character string length 10 NOT NULL teach_name: variable length character string length 10 NOT NULL) Primary Key: teach_num which integrity constraint is satisfied?
A) Entity integrity
B) Necessary data
C) Referential integrity
D) Referential foreign integrity

Question

Quizplus · Accepted Answer

Entity integrity is satisfied because the primary key, teach_num, is defined as NOT NULL, ensuring that each teacher has a unique identifier.

Consider the Following DBDL Description of an Entity: Teachers (Teach_num