RELACIONI MODEL

RELACIONI MODELS1Sif ucenikaMLBImeStarostSif smera10909998715564Ana150120908997710698Mirko170130102999710478Zoran1602S2Sif ucenikaMLBImeStarostSif smera20908997710698Mirko170130102999710478Zoran160240505996710456Milos1801S3=S1S2Sif ucenikaMLBImeStarostSif smera10909998715564Ana150120908997710698Mirko170130102999710478Zoran160240505996710456Milos1801UNIJAS4=S1-S2Sif ucenikaMLBImeStarostSif smera10909998715564Ana1501S4=S2-S1Sif ucenikaMLBImeStarostSif smera40505996710456Milos1801RAZLIKAS5=S1S2Sif ucenikaMLBImeStarostSif smera20908997710698Mirko170130102999710478Zoran1602PRESEKDEKARTOV PROIZVOD

ProjekcijaGraaninMlbImeStarostMesto0807..Ana19Bg0907...Mirko21Va2706...Zoran20Bg0407...Ana19Ni2503...Mirko21Bg2403...Zoran20Ns2401..Milo22BgProjekcija (ime, starost) GraaninImeStarostAna19Mirko21Zoran20Milo22Selekcija- Prikai graane koji su stariji od 20 godina i roeni u BgGraaninMlbImeStarostMesto0807..Ana19Bg0907...Mirko21Va2706...Zoran20Bg0407...Ana19Ni2503...Mirko21Bg2403...Zoran20Ns2401..Milo22BgPr2- (starost>20 and Mesto=Bg)MlbImeStarostMesto2503.Mirko21Bg2401.Milo22BgSpajanje ekvi i prirodno spajanjePr3=Graanin[graanin.mlb=ucenik.mlb]UenikGraaninMlbImeStarostMesto0807..Ana15Bg0907..Mirko17Va2706..Zoran20Bg0407..Ana19Ni2503..Mirko21Bg2403..Zoran16Ns2401..Milo18BgUenikSif ucMLBSif smera10807..0120907..0132403..0242401...01EKVI SPAJANJEMlbImeStarostMestoSif ucMlb

Sif smera0807..Ana15Bg10807..010907..Mirko17Va20907..012403..Zoran16Ns32403..022401..Milo18Bg42401...01PRIRODNO SPAJANJEMlbImeStarostMestoSif ucSif smera0807..Ana15Bg1010907..Mirko17Va2012403..Zoran16Ns3022401..Milo18Bg401NULA VREDNOSTI- NULLANDT?FTT?F???FFFFFORT?FTTTT?T??FT?FNOTTF??FTUNIJA R1R2R1ABaba??b??R2ABxy?b??ABaba??b??xYRAZLIKA R1-R2R1ABaba??b??R2ABxY?b??ABaba?SELEKCIJA S[A=a]R1R1ABaba??b??ABaba?PROJEKCIJA P[A]R1R1ABaba??b??Aa?EKVI SPAJANJER1AB12214?R2CD3422R1[A=C]R2 ABCD2122PRIRODNO SPAJANJER1AB12214?R2CD3422R1[A=C]R2 ABCD2122CENTRALNO SPAJANJER1AB12214?R2CD3422R1[A=C]R2 ABCD212212??4?????34LEVO SPAJANJER1AB12214?R2CD3422R1[A=C]R2 ABCD212212??4???DESNO SPAJANJER1AB12214?R2CD3422R1[A=C]R2 ABCD2122??34SPOLJNO SPAJANJER1ABCa1b1c1a2b1c2R2ADa14a17a25ABCDa1b1c1a2b1c2a1a1a2