Tebulo chilengedwe ntchito mu SQL - Pangani Table

Kugwira ntchito ndi zinasokoneza makompyuta mwachindunji zokhudzana ndi matebulo kusintha ndi deta iwo ali. Koma isanayambe kanthu pa tebulo kulenga. Pali wapadera SQL ntchito kwa automate mnjira - "Pangani MITU".

Chinthu choyamba!

Tisanafotokoze kuthana ndi ndondomeko ya kulenga spreadsheets ntchito MS SQL "Pangani MITU" lamulo m'pofunika kukhala pa zimene tiyenera kudziwa musanagwiritse ntchito kugwira ntchito.

Choyamba, muyenera ndi dzina la gome - ziyenera kukhala wapadera poyerekeza ndi ena Nawonso achichepere, ndi kutsatira malamulo ochepa. dzina ayenera kuyamba ndi kalata (Azariya), ndipo kenako padzatsatira makalata aliyense, manambala ndi kukutsimikizira, chifukwa mawu sayenera mawu wotetezedwa. dzina tebulo akhoza musalumphe zilembo 18.

Popeza tafotokozera dzina, kapangidwe ayenera anayamba: kubwera ndi mayina a mizati ntchito kuganiza mtundu izi deta ndi zimene minda ayenera kudzazidwa. Palinso nthawi yomweyo kudziwa munda kunja ndi makiyi chachikulu, ndipo n'zothekanso kuti achepetse makhalidwe deta.

Ena pa tebulo akhoza mwachilungamo mosavuta zina zabwino n'cholinga sitepe ya kulenga tebulo, iwo akhoza ankaganiza kuti kutha.

malembedwe

Kapangidwe ka matebulo, mukhoza chitani chilengedwe chake. Kophweka zokwanira, ntchito SQL ntchito "Pangani MITU". Pamafunika wosuta kuti mwatchutchutchu kale anapanga dzina tebulo ndi ndime mndandanda, kuwapatsa malangizo kwa mtundu uliwonse ndi dzina. malembedwe ali motere:

Pangani MITU table_name
({Column_name datatype [kusakhulupirika akuti] [column_constraint] ... | table_constraint}
[, {Column_name datatype [kusakhulupirika akuti ] [column_constraint] ... | table_constraint}] ...)

Mfundo ntchito mbali kapangidwe ali motere:

• table_name - dzina tebulo
• column_name - dzina Danga
• mtundu deta ntchito mu munda - datatype
• Pofikira - kumasonyeza ntchito mu ndime ya ofikira.

Ndi zotheka kugwiritsa ntchito awiri mfundo ntchito zambiri:

• Zokonda ndime - colum_constraint
• Zokonda tebulo - table_constraint

Mu iwo, wosuta akhoza kukhazikitsa ntchito wofunikila zofooka kapena zikhalidwe za kudzaza tebulo.

Features kulenga matebulo

Pamene akulemba afunsa kuti SQL "Pangani MITU" ntchito, ndi zina m'pofunika kukhazikitsa malamulo kudzaza m'minda. Kuti tichite zimenezi, muyenera kuwonjezera mbali makhalidwe wapadera kuti amaonetsera ina ya zinthu.

Pofuna kudziwa kufunika kanthu, ndiye mwachindunji dzina ndi mtundu wa mzati ayenera kulembetsa wina mawu ofunika pakhoza kukhala mu chipinda: NULL (kungakhale mfundo null), kapena ayi NULL (kumunda ayenera kudzazidwa).

Polenga tebulo nthawi zambiri chofunika choti aliyense mbiri kupewa ndi ziwiri zofanana. Kuchita kawirikawiri ntchito mzere manambala. Ndipo, chotero, si monga amafuna wosuta chidziwitso cha nkhani atsopano, kupezeka mu gome, ndi kugwira ntchito "Pangani MITU" yokwanira mwachindunji chachikulu kiyi ndime polemba nfundo yaikhulu "Pulayimale mfungulo" pambuyo munda kake. Nthawi zambiri, ndi kiyi choyambirira ndipo pali kugwirizana pakati pa matebulo.

Kuti Mangirirani mahatchi kugaleta ndi makiyi a Pulayimale ntchito ndi lachilendo kiyi chuma "FOREIGN LOFUNIKA". Analoza mzati, katundu uyu akhoza anaonetsetsa kuti m'munda umenewu adzakhala ali mtengo chomwecho monga mmodzi wa anthu amene ali choyambirira kiyi ndime ya magome kapena osiyana. Motero samalani kuti deta.

Kupereka yotsimikizira kuti litsatidwe ena akonzedwa mwachindunji kapena tanthauzo la, ntchito chikhumbo ZAKE. Iye chinafotokoza atsopano mu mndandanda wa mfundo kugwira ntchito, ndipo monga chizindikiro munthu ali ndi mawu Buliyani. Ndi izo, inu mukhoza asagwiritse mndandanda wa mfundo zotheka Mwachitsanzo, ntchito tebulo munda "Gender" kokha zilembo "M" ndi "F".

Kupatulapo amene anapereka, ndi SQL ntchito "Pangani MITU" ali ndi makhalidwe akadali ambiri zenizeni, koma ntchito kuchita ndi zochepa wamba.

zitsanzo

Kuti bwino ntchito kugwira ntchito, ndi bwino kuganizira kuchita, mmene kulenga MITU (SQL). Mwachitsanzo pansipa amalenga tebulo anapereka m'munsimu:

Pangani MITU Mwambo
(ID Char (10) OSATI NULL Pulayimale kiyi
Custom_name Char (20)
Custom_address Char (30)
Custom_city Char (20)
Custom_Country Char (20)
ArcDate Char (20))

Monga mukuonera, atakhala zotheka chosowa mtengo mu maselo (NULL) tingalisiye, popeza ntchito zotsatira.