Page 12 - الحاسب الآلي ثانية إرشاد 2

‫أﻧﻈﻤﺔ ﻗﻮاﻋﺪ اﻟﺒﻴﺎﻧﺎت‬ ‫اﻟﻔﺼﻞ اﻷول‬

relation schema

sid, name, login, ) ‫ ﻓ‬students

(age, gpa

Faculty(fid: string, fname: string, sal: real)

Courses(cid: string, cname: string, credits: integer)
Rooms(rno: integer, address: string, capacity: integer)

‫ ﻤﺜﺎل‬. ٤ relations

Relation

sid name Login age Gpa
١٥ ٢١ v.good
٢٧ ٢٠ Good
٣٩ ٢٢ Excellent

instance ‫ ﻴﺴﻤﻲ‬Relation

courses Students
rooms Courses
Courses faculty
relation

One-to-One (1:1) ‫ﻋﻼﻗﺔ‬

١٢