Me pēhea te ki te tuhituhi SQL-pātai - tauira ngā

Takitaha o tatou anga wā me whakamahi te whānuitanga o ngā pātengi. A, no te whiriwhiri tatou i te wāhitau ī-mēra, kei te mahi matou ki te pātengi raraunga. pātengi raraunga mā te whakamahi i ngā ratonga rapu, pareparenga mo te rokiroki o ngā raraunga kiritaki, me ētahi atu

Otiia ahakoa te whakamahi tonu o te pātengi raraunga, ara mo te maha ngā pūnaha pūmanawa ngā Ko te rota o "wahi ma" e tika ana ki tikanga rerekē o te taua ngā. hoatu matou he whakamāramatanga poto o te ngā matua ki pātengi o whakaaro SQL. Reira.

Pātengi Raraunga - he kōnae ranei whakaturia o ngā kōnae mō te pupuri i ngā hanganga raraunga whakahau me ratou whanaungatanga. Tino maha, ka karanga te pātengi raraunga ko te pūnaha whakahaere pātengi raraunga (DBMS). Pātengi Raraunga - te reira i te pätaka tika o ngā mōhiohio i roto i te hōputu motuhake a taea te mahi ki te pātengi raraunga rerekē.

Ripanga - whakaaro te kōpaki i roto i nei e penapena tuhinga, whakarōpū rite ki etahi tawhā, pērā i te rārangi o whakahau mo te marama whakamutunga. Ko te tepu i roto i te rorohiko tenei pātengi raraunga. he ona ake ingoa motuhake te tepu motuhake.

Momo Raraunga - te momo o ngā mōhiohio whakaaetia ki te penapena i roto i te tīwae kotahi rarangi ranei. E nehenehe te reira i te hōputu tau kuputuhi ranei motuhake.

Tīwae me te rarangi - mahi matou katoa ki ripakaute, i he hakari nga rarangi, me tīwae roto hoki. Tetahi pātengi raraunga tūhonohono mahi ki nga tepu te ara ano. E te tahi mau taime i huaina aho pūkete.

He kī tuatahi - kia whai ia rarangi kotahi, neke atu rānei tīwae hoki tona tuakiri ahurei. Ko te tino uaua No kī tuatahi ki te whakahou, te whakarerekē me te muku rarangi e hāngai ana.

He aha te mea SQL?

reo uiui SQL (. English hanganga Uiui Reo - Whakaraupapa Reo Uinga) i hangaia anake ki te mahi ki pātengi raraunga, me te ko tēnei wā te paerewa mō pātengi rongonui katoa. hanga te wetereo reo ake o te maha iti o ngā me ngāwari ki te ako. Otiia ahakoa te tapatahi kitea, taea reira te hanga o uiui SQL mō ngā mahi matatini ki te pātengi raraunga o tetahi rahi.

Mai 1992, i reira te mea he paerewa noa, ka karanga ANSI SQL. tautuhi te reira i te wetereo taketake me mahi o ngā me e tautokona e te katoa kau taki mākete DBMS, pērā i te ahurewa te Microsoft te Tūmau SQL. Whakaaroa nga āhuatanga katoa o te reo i roto i te tuhinga poto e taea, na ka whakaaro poto tatou i te uiui SQL taketake anake. whakaatu tauira te tapatahi me ngā āhuatanga o te reo:

• te hanga pātengi me tepu;
• tīpakonga raraunga;
• Tāpiri tāurunga;
• whakarerekētanga me te mukunga o te mōhiohio.

Ngā momo SQL Raraunga

tīwae katoa i roto i te ripanga pātengi raraunga rokiroki i te momo raraunga taua. i roto i te SQL momo raraunga e te taua rite i roto i ētahi atu reo hōtaka.

momo raraunga	whakaahuatanga
INT	tau tōpu
REAL	Māngi tau ira
KUPU	string Pūāhua o te roa tāupe
DATE	SQL uiui "te rā" i roto i te whānuitanga o ngā hōputu
TIME	wā
Pūāhua	aho Text o te roa i whakaritea

Waihanga tepu me pātengi

Waihanga pātengi hou, tepu, me ētahi atu pātai i roto i SQL E rua huarahi:

• tauākī SQL roto i te papatohu pātengi raraunga
• Mā te pāhekoheko taputapu Whakahaere, he wahi o te tūmau pātengi raraunga.

He operator pātengi raraunga hōu Waihangaia he DATABASE ; . Ka rite ki a koutou e taea te kite, he kuware, me te poto o te wetereo.

Ko te tepu i roto i te pātengi raraunga te waihanga i te FAU TÜTOHI tauākī ki te tawhā e whai ake nei:

• ingoa ripanga
• ingoa me raraunga momo o tīwae

Ka rite ki te tauira, te hanga i tētahi tepu Commodity ki te pou e whai ake nei:

tīwae	whakaahuatanga
commodity_id	ID hua
vendor_id	Kaihoko ID (Vendors matua ripanga waho)
commodity_name	ingoa hua
commodity_price	utu o
commodity_desc	whakaahuatanga

Waihanga i te tepu:

Waihangaia he TABLE Commodity

(Pūāhua commodity_id (15) Kāore i korengia,

vendor_id Char (15) Kāore i korengia,

commodity_name Char (254) i korengia,

Ira commodity_price (8,2) i korengia,

commodity_desc VARCHAR (1000) i korengia);

Kei roto i te tepu e rima tīwae. I muri i te ingoa ko te momo o tīwae raraunga e wehea e te piko. Ka taea e te uara tīwae amo uara korenga (i korengia) ranei me ki tonu i roto i (Kāore i korengia), a ko reira fakapapau'i ki te hanga i te ripanga.

raraunga Tauira i te tepu

tīpako operator raraunga - te uiui SQL tino whakamahia nuitia. Mō ētahi atu pārongo e hiahia ana koe ki te whakapūtā e hiahia ana tatou ki te tīpako i te tepu. I te tuatahi he tauira ohie:

commodity_name Tīpakohia MEI Commodity

I muri i te tauākī Tīpakohia tohu te ingoa o te tīwae ki te tiki mōhiohio, engari tāutu MEI te tepu.

te hua rapu ka hei rarangi tepu katoa ki uara Commodity_name i te raupapa i roto i nei i tomo ratou ki roto ki te pātengi raraunga i.e. kahore tetahi kōmaka. Hei whakarite i nga hua mā te whakamahi i te ORDER kaiwhakahaere kōwhiringa BY.

Hei te uiui i runga i ngā āpure maha whakarārangi wehea ratou e ngā piko rite i roto i te tauira e whai ake nei:

commodity_id Tīpakohia, commodity_name, commodity_price MEI Commodity

Ko taea ki te tiki rite hua o te uara rapu string o tīwae katoa. Hoki tenei whakaaro, i te tohu "*":

* Tīpakohia MEI Commodity

• WHIRIWHIRI I ato'a tautoko:
• raraunga Kōmaka (ORDER BY tauākī)
• Tīpakonga rite ki nga tikanga (HEA)
• Whakarōpū wā (GROUP BY)

tāpiri i te rārangi

Hei tāpiri rarangi ki te tepu te whakamahi i tauākī SQL ki tauākī WHAKAURUA. Ka taea te hanga e te tua i roto i te huarahi e toru:

• tāpiri i te aho katoa hou;
• o te aho;
• hua uiui.

Hei tāpiri i te raina oti, me whakapūtā koe te ingoa tepu me nga uara o tīwae (mara) o te raina hou. Tenei ko te tauira:

Kōkuhu ki uara Commodity ( '106', '50', 'Coca-cola', '1.68', 'No Alcogol,)

tāpiri tauira te hua hou ki te tepu. E tohua Uara i muri i uara mō ia tīwae. Ki te kahore he uara hāngai mo te tīwae, he mea e tika ana ki te tautuhi i korengia. Kei te ki tonu nga tīwae me ngā uara i roto i te tikanga i whakaritea ka hanga i te tepu.

I roto i te take o te tāpiri i te wahi anake o te aho me āta whakapūtā te ingoa o te tīwae, pera i roto i te tauira:

WHAKAURUA KI Commodity (commodity_id, vendor_id, commodity_name)

Uara ( '106', '50', 'Coca-cola', )

Kua whakaurua matou pūwehe hua anake, kaiwhakarato, me tona ingoa, a ka hoatu te toenga o te parae peka kau.

Tāpiri hua uiui

Fele, whakamahia WHAKAURUA te ki te tāpiri i te rarangi, engari e taea te whakamahi mō te tāpiri i te hua tauākī Tīpakohia.

huringa raraunga

Hei huri te mōhiohio i roto i ngā āpure i te ripanga pātengi raraunga Me ki te whakamahi i tētahi tauākī WHAKAHOU. Ka taea te whakamahi i te kaiwhakahaere i roto i ara e rua:

• Whakahoutia nga rarangi katoa i roto i te tepu.
• Anake hoki etahi he aho.

ngā WHAKAHOU o e toru ngā huānga matua:

• he tepu i roto i nei e hiahia ana koe ki te hanga i ngā huringa;
• ingoa mara, me o ratou uara hou;
• Here mo nga huringa haupae whiriwhiri.

Fakakaukau angé ki he tauira. Kia mea a te hua ki te ID = 106 kua puta ke te utu, na tenei raina ki te whakahou. Tuhia te parau i muri nei:

WHAKAHOU Commodity WHAKARITE commodity_price = '3.2' HEA commodity_id = ' 106'

tuhu atu tatou i te ingoa tepu, i roto i tenei take, te Commodity, ka e kia whakahoutia, a ka i muri i te WHAKARITE - te uara hou o te tīwae, me te kitea i te tūemi e hiahiatia ana, te tauwhāiti i te ID uara HEA hiahiatia.

Hei huri i te maha o tīwae muri āta te tauākī WHAKARITE e rave rahi takirua o tīwae-uara, wehea e ngā piko. Tirohia te he tauira ingoa me te utu o nga taonga i roto i nei te whakahōutia:

WHAKAHOU Commodity WHAKARITE commodity_name = 'Fanta' , commodity_price = '3.2' HEA commodity_id = ' 106'

Hei muku te mōhiohio i roto i te tīwae, ka taea e whakaturia e koe i te reira ki te whakakahore, ki te taea reira te hanganga o te tepu. Me mahara te reira e te korengia - ko te "kahore" uara tenei, e kore e kore rite kuputuhi tau ranei. Tangohia te whakaahuatanga tūemi:

WHAKAHOU Commodity WHAKARITE commodity_desc = korengia HEA commodity_id = ' 106'

E mukua rarangi

E whakamana tono SQL ki te muku rarangi i roto i te tepu kaiwhakahaere Muku. E rua huarahi ki te whakamahi i:

• mukua Ripanga etahi rarangi;
• nekehia atu nga rarangi katoa i roto i te tepu.

TAUIRA tango tetahi rarangi o te tepu:

MUKU MAI Commodity HEA commodity_id = '106'

I muri DELETE MAI whakarite te ingoa tepu i roto i nei ki te muku rarangi. HEA operator ngā te huru i raro nei e aho e tīpakohia mō te mukua. I roto i te tauira tango tatou i te rārangi hua ki ID = 106. tohu HEA tino nui no te haere tango i tenei privedt kaiwhakahaere rarangi katoa i roto i te tepu. E pā ana tēnei ki te huri i ngā uara te mara.

E kore e te tauākī Mukua whakapūtā ingoa tīwae, me meta-pūāhua. Ia tino tango te aho, me te muku i te tīwae kotahi, e kore e taea e ia.

Mā te SQL i roto i Microsoft Access

Microsoft Access Kei te nuinga whakamahia whakawhitinga ki te waihanga i tētahi ripanga, pātengi raraunga, huringa whakahaere, te tātaritanga o ngā raraunga i roto i te pātengi raraunga, me te i roto i te tikanga ki te whakatinana i te Uru pātai SQL mā te watea kaihanga rapu pāhekoheko (Designer Uiui), mā te whakamahi i nei e taea e koe te hanga, me te mahia tonu tauākī SQL tetahi whīwhiwhi.

tautoko hoki aratau uru ki te tūmau, e taea te whakamahi ai te Access pātengi raraunga rite SQL-uiui generator ki tetahi puna raraunga ODBC. Tēnei āhuatanga e āhei ngā tono ki te kōrero ki te Access pātengi raraunga i roto i tetahi hōputu.

toronga SQL

No te mea e kore pātai SQL e whai i nga āhuatanga tukanga katoa reo hōtaka pērā i koropiko, kouru, me ētahi atu, te whakawhanake i nga kaiwhakanao DBMS ratou putanga o SQL ki ngā āhuatanga arā atu anō. Ko te tuatahi ko te tautoko hoki ngā tukanga rongoa me ngā paerewa reo tukanga.

Ko te reo te nuinga noa o te reo:

• Oracle Pātengi Raraunga - PL / SQL
• Interbase, Firebird - psql
• Tūmau SQL Microsoft - faatere i-SQL
• PostgreSQL - PL / PGSQL.

Internet SQL

tukua MySQL pātengi raraunga te i raro i te raihana free Raihana GNU General Public. He he he raihana arumoni ki te kaha ki te whakawhanake i kōwae ritenga. Hei wāhanga o te wahi tino rongonui o te tūmau hanga Ipurangi pērā i XAMPP, WAMP ko rama, a ko te tino rongonui whanaketanga tono pātengi raraunga i roto i te Internet.

I whakawhanakehia te reira e Sun Microsystems me te tautoko i tēnei wā e Oracle. Tautoko rahi ake pātengi raraunga ki te 64 terapaita, te wetereo SQL: 2003, replicating pātengi me ngā ratonga kapua.