Senotlolo sa basele se bula monyako oa lefats'e lohle la dintlha
Basebelisi ba ditshwantsho ba basebetsi ba sebelisa mefuta e mengata ha ba ntse ba ntlafatsa boitsebiso ba metsoalle. E 'ngoe ea lisebelisoa tsena tse tloaelehileng ke lisebelisoa tsa mantlha le likhetho tsa linaheng tse ling Sesekelo sa kantle ho marang-rang ke tšimo tafoleng e amanang le eona e lumellanang le khoeli ea motheo ea tafole e 'ngoe. Ho utloisisa hore na senotlolo se tsoang linaheng tse ling se sebetsa joang, a re ke re hlahlobisiseng maikutlo a ditshwantsho tsa setsoalle.
Lintlha tsa motheo tsa Boitsebiso bo Amanang
Lefapheng la litaba, litlaleho li bolokoa ka litafole tse nang le mela le lihlopha, ho etsa hore ho be bonolo ho batlisisa le ho tsamaisa. Ho na le lipalo tse matla ka morao ho mohopolo oa database relational (relational algebra, e hlophisitsoeng ke EF
Codd ho IBM ka 1970), empa ha se taba ea sehlooho sena.
Bakeng sa merero e sebetsang (le bao e seng litsebi tsa lipalo), dintlha tsa basebetsi li boloka dintlha tse "amanang" ka mela le mela. Ho feta moo-mme mona ke moo e fumanang thahasellisang-marang-rang a mangata a entsoe e le hore data e tafoleng e le 'ngoe e ka fihlella lintlha tse ling tafoleng e' ngoe. Bokhoni bona ba ho bōpa likamano lipakeng tsa litafole ke matla a nnete a database ya relational.
Ho Sebelisa Litsela tsa Linaha Tsa Linaha
Boholo ba litafole, haholo-holo tse maqepheng a maholo, a rarahaneng, li na le linotlolo tse ka sehloohong. Mehala e etselitsoeng ho fumana litafole tse ling e tlameha ho ba le senotlolo sa kantle.
E le hore u sebelise database ea Northwinds e boletsoeng ka tloaelo, bona ke karolo e hlahang tafoleng ea Product:
| ProductID | ProductName | CategoryID | PaloPerU | Theko ea thepa ka 'ngoe |
|---|---|---|---|---|
| 1 | Chai | 1 | Mabokoseng a 10 x mekotla e 20 | 18.00 |
| 2 | Phetoho | 1 | Li-bottle tse 24 - 12 oz | 19.00 |
| 3 | Syrup e nang le anise | 2 | Li-bottle tse 12 - 550 ml | 10.00 |
| 4 | Cajun Season Chef ea Chef | 2 | 48 - 6 litsu tse 6 | 22.00 |
| 5 | Mofuthu oa Anton oa Gumbo | 2 | Mabokose a 36 | 21.35 |
| 6 | Nkhono oa Boysenberry oa Hasana | 2 | 12 - 8 oz linkho | 25.00 |
| 7 | Malome Bob's Organic Pears a omisitsoeng | 7 | 12 - 1 lb pkgs. | 30.00 |
Sehlooho sa ProductID ke sesebelisoa se ka sehloohong sa tafole ena. E fana ka ID e khethehileng ho sehlahisoa se seng le se seng.
Tafole ena e boetse e na le khoeli ea kantle ho naha, CategoryID . Sehlahiswa se seng le se seng tafoleng ea Product se amahanya le ho kena lihlopha tsa lihlopha tse hlalosang sehlahisoa sa sehlahisoa seo.
Hlokomela sena se hlahang ho tloha tafoleng ea Categories ea database:
| CategoryID | CategoryName | Tlhaloso |
|---|---|---|
| 1 | Lijo | Lijo tse bonolo, li-coffees, teas, biri le li-ales |
| 2 | Litumellano | Li-sauces tse monate le tse monate, li tsosolosa, li jala, le lihlahisoa |
| 3 | Litumelo | Li-dessert, li-candies le li-sweetbreads |
| 5 | Lihlahisoa tsa Mafura | Lijoe |
Sehlopha sa IDC se ka sehloohong se ka sehloohong sena. (Ha e na senotlolo sa kantle ho naha kaha ha e na tlhokahalo ea ho fihlela tafoleng e 'ngoe.) Ntho e' ngoe le e ' Ka mohlala, sehlahisoa sa Chai se abeloa karolo "Beverages", ha Aniseed Syrup e le sehlopheng sa Condiments.
Mofuta ona oa ho kopanya o baka mekhoa e mengata ea ho sebelisa le ho sebedisa dintlha ditsheng tsa ditshwantsho.