Chimodzi mwa mfundo zofunika kwambiri m'mabuku ndikupanga mgwirizano pakati pa matebulo a deta. Ubale umenewu umapereka njira zogwirizanitsa deta yosungidwa m'matawuni ambiri ndikuulandira bwino. Kuti mupange mgwirizano pakati pa matebulo awiri, muyenera kufotokoza makiyi akunja mu tebulo limodzi lomwe limatchula ndondomeko mu tebulo lina.
Madiresi Achidindo ndi Ubale
Mwinamwake mukudziwa kuti mazenerawa ndi ma tebulo angapo , ofanana ndi zomwe mungagwiritse ntchito pulogalamu ya spreadsheet , monga Microsoft Excel. Ndipotu mungathe kusintha ngakhale pulogalamu ya Excel ku deta. Momwe mazenera amasiyanasiyana kuchokera ku spreadsheets, komabe, ndikufika pa kukhazikitsa ubale wamphamvu pakati pa matebulo.
Mwachitsanzo, taganizirani deta yomwe kampani ikugwiritsira ntchito kuti mudziwe zambiri zokhudza anthu. Deta yapamwambayi ikhoza kukhala ndi tebulo lotchedwa Workers yomwe ili ndi mfundo zotsatirazi kwa aliyense wa antchito a kampani:
- ID ya ogwira ntchito
- Dzina loyamba
- Dzina lomaliza
- OfficePhone
- HomePhone
- PositionID
Mu chitsanzo ichi, ID ya ogwira ntchito ndi yeniyeni yapadera yomwe imaperekedwa kwa wogwira ntchito aliyense pamene iwonjezedwa ku deta. Malo ID ndizolemba ntchito yogwiritsidwa ntchito poyang'ana udindo wa wogwira ntchito mu kampani. Pachifukwa ichi, antchito akhoza kukhala ndi malo amodzi okha, koma antchito angapo (kapena ayi) akhoza kudzaza malo awo onse. Mwachitsanzo, mungakhale ndi antchito mazana ambiri omwe ali ndi "Cashier" udindo.
Mndandanda wa malowa ukhoza kukhala ndi tebulo lotchedwa Positions ndi mfundo zotsatirazi zowonjezera pa malo alionse:
- PositionID
- Mutu
- JobLevel
- SkillCategory
- Malo
Makhalidwe a Pulogalamuyi mu tebulo ili ndi ofanana ndi gawo la Employee ID mu tebulo la Akazi - ndilopadera lopangidwa ndipadera pamene malo akuwonjezeredwa ku database.
Pamene tipita kukatulutsa mndandanda wa antchito kuchokera ku databata, zingakhale zachibadwa kupempha dzina la munthu aliyense ndi dzina lake. Komabe, mfundoyi imasungidwa m'matawuni ambirimbiri, kotero ikhoza kubwezedwa pogwiritsa ntchito JOIN funso lomwe limafuna mgwirizano ulipo pakati pa matebulo.
Mukayang'ana kapangidwe ka matebulo, munda womwe umatanthauzira ubalewo ndiwonekeratu - malo a malo omwe alipo. Wogwira ntchito aliyense akhoza kukhala ndi malo amodzi okha ndipo malowa amadziwika mwa kuphatikizapo Pulogalamu ya ID kuchokera muzowonjezera pazithunzi za Positions. Kuphatikiza pa kukhala chinsinsi chachikulu pa tebulo la malo, mu chitsanzo ichi, malo a malo otchuka ndichinsinsi chakunja kuchokera ku ganyu la antchito mpaka pa tebulo la malo. Mndandanda wazamasamba ukhoza kugwiritsa ntchito mundawu kuti uwonetsane mauthenga kuchokera ku matebulo angapo ndikuonetsetsa kuti kusintha kulikonse kapena kuonjezera ku databoloko kumapitiriza kuonetsetsa kusasunthika .
Mukapeza chinsinsi chachilendo, mutha kupita patsogolo ndikukakulanso zomwe mukufuna ku database pogwiritsa ntchito funso ili:
Kupanga Makina Achilendo ku SQL Server
Mwachidziwikire, simukufunikira kufotokoza ubalewu momveka kuti ukhoza kupanga mafunso ngati omwe ali pamwambawa. Komabe, ngati mutanthauzira momveka bwino mgwirizano pogwiritsa ntchito chinsinsi chamtundu wachilendo, deta yanu idzatha kugwira ntchito ina yosungiramo nyumba:
- Mukamaonjezera mauthenga atsopano pa tebulo la ogwira ntchito, deta yanu idzaonetsetsa kuti chizindikiro cha malo omwe mumalowa ndicho chofunikira chofunikira pa tebulo la ntchito.
- Ngati mutasintha chizindikiro cha malo mu tebulo la malo, databata ikhoza kuchita zofunikira zowonjezera pa tebulo la ogwira ntchito kuti zisunge.
- Mndandanda wa mabanki ukhoza kuteteza motsutsana ndi zotsatira za kuchotsedwa kwa malo kuchokera pa tebulo lapamwamba mwa kukana kuchotsa malo ndi ofanana nawo ntchito zolembera kapena kuchita kutsekemera kuchotsa antchito onse ofanana.
Nazi momwe mungapangire chinsinsi chachilendo ku SQL Server:
ALTER TABLE Ogwira ntchito PEZANI ZINTHU ZOFUNIKA KWAMBIRI (PositionID) ZOKHUDZA MAFUNSO Malo (PositionID)Mutha kukhazikitsa makiyi akunja pamene mukupanga tebulo powonjezera ndimeyi:
ZINTHU ZOFUNIKA ZOFUNIKA KWAMBIRI Malo (PositionID)mpaka kumapeto kwa ndondomeko yachitsulo chachitsulo chachilendo chakunja.