【2019年8月】OCP 071認證考試最新版本的考試原題-第17題

choose two

Examine this business rule:

Each studert can work on mutiple projects and eath project can have multiple students

You must desion an Entity Relationsep (ER) model for optional data storage and allow generating reports in this format:

STUDENT_ID FIRST_NAME LAST_NAME PROJECT_ID PROJECT_NAME PROJECT_TASK

Which two statements are true?

A) An associative table must be created with a composite key of STUDENT_ID and PROJECT_ID,which is the foreign key linked to the STUDENTS and PROJECTS entities.

B) The ER must have a many-to-many relationship between the STUDENTS and PROJECTS entities that must be resolved into 1-to-many relationships.

C) PROJECT_ID must be the primary key in the PROJECTS eitity and foreign key in the STUDENTS entity.

D) The ER must have a 1-to-many relationship between the STUDENTS and PROJECTS entities.

E) STUDENT_ID must be the primary key in the STUDENTS entity and foreign key in the PROJECTS entity.

Anaswer：AB

(解析：這道題涉及到調優問題，應用中常常出現多對多之間的關係，如何解決 STUDENTS and PROJECTS 兩張表的多對多關係，能夠建立一箇中間表，這個表包含那兩張表的主鍵列，同時是另外兩張表的外鍵約束。一般這個表建成索引組織表。)