Cc ni dung chnh

Cc bc thit k mt CSDLV d minh ha

Thit k C s d liu

Chuyn t m hnh thc th lin kt sang m hnh quan h.

Xc nh cc ph thuc hm t cc rng buc d liu v cc quy tc nghip v.

Chun ha cc lc quan h, a chng v cc lc dng chun 3.

B sung thm cc thuc tnh kha nu cn, nht l khi quan h c nhiu thuc tnh kha.

Xc nh chi tit cc min gi tr cho cc thuc tnh, t xc nh kiu d liu cho chng. Lp bng m t chi tit cc kiu d liu ca tng thuc tnh cho tng quan h (bng)

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V d v TK CSDL

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Tn thc thTn s dngCc thuc tnhKhoaTKhoaTn khoa, Vn phng, in thoi, FaxB mnTBoMonTn BM, Vn phngGio vinTGiaoVienTnGV, Ngy sinh, a ch, Chc danh, Chc v, Ngy chc danh, Ngy chc vLp hcTLopHocTn lp, Kha hc, S Lng SVPhng hcTPhongTn phng, SL ch ngiTrng BMTTrBMGm cc thuc tnh ca Gio vin, Ngy nhm chc, Ngy thi chcThi kha biuTKBNm hc, Hc k, Khoa, Lp hc, Phng hc, Mn hc, Tit hc Khi lng ging dyKLGDTKB, Gio vin

V d v TK CSDL

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Khoa

Lp hc

Phng hc

TKB

Gio vin

N

N

B mn

KLGD

1

1

1

N

N

N

N

N

1

1

1

1

N

1

Trng B mn

1

1

Cc bng c suy ra

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Bng KhoaThuc tnhTn khoa, Vn phng, in thoi, FaxRng buc & Quy tc nghip vPh thuc hmMi khoa c 1 vn phngV thng mi VP thuc v mt khoa, v vic chuyn a im lm vic ca khoa rt him khi xy raTn khoa Vn phng;Mi vn phng c mt s fax v c th c nhiu s in thoiVn phng FaxChun ha:Kha: K = (Tn khoa, in thoi); Vi phm chun 2 v 3Tch thnh 3 quan h:Khoa (Tn khoa, Vn phng);VnPhng (Vn phng, Fax);inThoiKhoa (Tn khoa, in thoi);Ghi ch: c th cn nhc vic ghp 2 bng Khoa v Vn phng do mi qh gia 2 bng ny.

Cc bng c suy ra

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Bng Gio vinThuc tnhTnGV, Ngy sinh, a ch, Chc danh, Ngy chc danh, Chc v, Ngy chc vRng buc & Quy tc nghip vPh thuc hmMi GV c 1 ngy sinhTnGV Ngy sinh;Mi GV c th c nhiu a ch, nhng mi thi im th ch c 1 chc danh v nhiu nht l 1 chc v (c th khng c).TnGV, Ngy chc danh Chc danh;TnGV, Ngy chc v Chc vChun ha:Kha duy nht: K = (TnGV, a ch, Ngy chc danh, Ngy chc v)Vi phm chun 2; Tch thnh 4 quan h:GioVin (TnGV, Ngy sinh);GV-a ch (TnGV, a ch, Ngy chc danh, Ngy chc v);GV-Chc danh (TnGV, Ngy chc danh, chc danh);GV-Chc v (TnGV, Ngy chc v, chc v);

Ghp 2 bng B mn v Trng BM

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Bng B mnThuc tnhTnBM, Vn phng, Trng BM, Ngy nhm chc, Ngy thi chcRng buc & Quy tc nghip vPh thuc hmMi B mn c 1 Vn phngTnBM Vn phng;Mi trng BM c 1 ngy nhm chc v 1 ngy thi chc mi thi im th 1 BM ch c 1 trng BMTrng BM Ngy nhm chc, ngy thi chcTn BM, Ngy nhm chc Trng BMChun ha:Kha: K1 = (TnBM, Trng BM); K2 = (Tn BM, Ngy nhm chc)Vi phm chun 2; Tch thnh cc quan h:B mn (Tn BM, Vn phng);TrngBM (TrngBM, Ngy nhm chc, Ngy thi chc);BM-TrngBM (Tn BM, Ngy nhm chc, Trng mn);

Cc bng c suy ra

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Bng TKBThuc tnhNm hc, Hc k, Tn Khoa , Tn lp, Tn phng, Mn hc, Tit hc Rng buc & Quy tc nghip vPh thuc hmMi lp hc thuc mt khoaTn lp Tn Khoa;Mi mn hc ca mt lp trong mt nm hc v 1 hc k th hc 1 tit hc phi hc 1 phng Nm hc, Hc k, Tn lp, Mn hc, Tit hc Tn phng;Chun ha:Kha duy nht: K = (Nm hc, Hc k, Tn lp, Tn phng, Tit hc)Vi phm chun 2; Tch thnh cc quan h:Lp hc (Tn lp, Tn khoa);TKB (Nm hc, Hc k, Tn lp, Tn phng, Tit hc, Tn phng);

B sung cc thuc tnh kha v xc nh min gi tr cho cc thuc tnh

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Bng KhoaThuc tnhKiu d liuRng bucIDintPKTnKhoaVarchar(200)Not NULLID_VPintFK to VnPhng(ID)Bng Vn phngThuc tnhKiu d liuRng bucIDintPKTn VPVarchar(200)Not NULLFaxVarchar(20)Dy cc ch s lin tipBng inThoiKhoaThuc tnhKiu d liuRng bucIDintPKID_KhoaIntFK to Khoa(ID)inThoiVarchar(20)Dy cc ch s lin tip

Cm n!