Cov txheej txheem:
Video: Vim li cas koj thiaj tsim kev sib raug zoo ntawm cov rooj?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
A kev sib raug zoo ntawm rooj yog ib qho tseem ceeb ntawm kev sib raug zoo database. 1) Nws tsim kev sib txuas nruab nrab ib khub rooj uas yog logically ntsig txog rau ib leeg. 2) Nws pab rau refine table structures thiab txo cov ntaub ntawv tsis tu ncua.
Ib yam li ntawd, koj tuaj yeem nug, lub hom phiaj ntawm kev sib raug zoo hauv cov ntaub ntawv yog dab tsi?
A kev sib raug zoo , nyob rau hauv cov ntsiab lus ntawm databases , yog qhov xwm txheej uas muaj nyob nruab nrab ntawm ob qho kev sib raug zoo database cov rooj thaum ib lub rooj muaj tus yuam sij txawv teb chaws uas hais txog qhov tseem ceeb ntawm lwm lub rooj. Kev sib raug zoo cia kev sib raug zoo databases cais thiab khaws cov ntaub ntawv hauv cov rooj sib txawv, thaum txuas cov khoom sib txawv.
Kuj Paub, koj ua li cas tsim kev sib raug zoo ntawm ob lub rooj hauv SQL? Siv SQL Server Management Studio
- Hauv Object Explorer, right-click lub rooj uas yuav nyob rau sab nraud-qhov tseem ceeb ntawm kev sib raug zoo thiab nyem Tsim.
- Los ntawm Table Designer ntawv qhia zaub mov, nyem Relationships.
- Nyob rau hauv lub Foreign-key Relationships dialog box, nyem Ntxiv.
- Nyem qhov kev sib raug zoo nyob rau hauv cov npe Xaiv Kev Sib Raug Zoo.
Tsis tas li ntawd, koj txhais li cas kev sib raug zoo ntawm cov ntxhuav hauv database?
A kev sib raug zoo yog tsim los nruab nrab ntawm ob lub rooj database thaum ib rooj siv tus yuam sij txawv teb chaws uas hais txog tus yuam sij tseem ceeb ntawm lwm rooj . Qhov no yog lub ntsiab lus tseem ceeb tom qab lub sij hawm kev sib raug zoo database.
Koj pom kev sib raug zoo ntawm cov rooj li cas?
Saib cov lus sib raug zoo
- Nyem Cov Ntaub Ntawv, thiab tom qab ntawd nyem Qhib.
- Xaiv thiab qhib lub database.
- Ntawm cov cuab yeej Database tab, hauv Pawg Kev Sib Raug Zoo, nyem Kev Sib Raug Zoo. Yog tias cov ntaub ntawv muaj kev sib raug zoo, lub qhov rais Kev Sib Raug Zoo tshwm.
- Ntawm Cov Tsim tab, hauv Pawg Kev Sib Raug Zoo, nyem Tag Nrho Kev Sib Raug Zoo.
Pom zoo:
Kev sib cav sib ceg sib txawv li cas ntawm kev sib cav tsis zoo?
Txhua qhov kev sib cav tsis zoo siv txoj cai invalid inference. Yog tias qhov kev sib cav tsis zoo koj paub tias nws tsis siv. Kev siv tau txhais tau tias tsis muaj kev txhais lus qhov twg qhov chaw muaj tseeb thiab qhov kev txiav txim siab tuaj yeem tsis tseeb ib txhij. Yog tias qhov kev sib cav ua txhaum koj tuaj yeem tsis quav ntsej nws thiab sim nkag siab lub ntsiab lus tseem
Puas txhais tau tias yog kev sib raug zoo ntawm cov khoom ntawm ib yam khoom thiab lub peev xwm ntawm tus neeg sawv cev uas muab cov lus qhia rau kev siv cov khoom?
Kev them nyiaj yog kev sib raug zoo ntawm cov khoom ntawm ib yam khoom thiab lub peev xwm ntawm tus neeg sawv cev uas txiav txim siab seb qhov khoom siv tau li cas
Vim li cas kev sib raug zoo algebra siv nyob rau hauv kev sib raug zoo database tswj?
RELATIONAL ALGEBRA yog ib hom lus nug uas siv dav heev. Nws sau cov xwm txheej ntawm kev sib raug zoo raws li kev tawm tswv yim thiab muab qhov tshwm sim ntawm kev sib raug zoo raws li cov zis. Nws siv ntau yam haujlwm los ua qhov haujlwm no. Relational algebra operations yog ua recursively ntawm kev sib raug zoo
Dab tsi yog qhov txawv ntawm kev sib raug zoo unary kev sib raug zoo binary thiab kev sib raug zoo ternary?
Kev sib raug zoo tsis sib xws yog thaum ob tus neeg koom hauv kev sib raug zoo yog tib lub koom haum. Piv txwv li: Cov ncauj lus yuav yog qhov yuav tsum tau ua ua ntej rau lwm yam kev kawm. Kev sib raug zoo ternary yog thaum peb lub koom haum koom nrog kev sib raug zoo
Dab tsi yog qhov txawv ntawm kev sib raug zoo thiab tsis muaj kev sib raug zoo databases?
Qhov sib txawv loj ntawm lawv yog li cas lawv tuav cov ntaub ntawv. Relational databases are structured.Non-relational databases are document-oriented. Qhov no hu ua cov ntaub ntawv hom cia tso cai ntau 'qeb' ntawm cov ntaub ntawv khaws cia hauv ib qho kev tsim lossis Cov Ntaub Ntawv