SQL Guide

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Mayelana nalolu hlelo lokusebenza

Umhlahlandlela we-SQL — Funda i-SQL, Isahluko Esisodwa Ngesikhathi

Umhlahlandlela we-SQL uhlelo lokusebenza lwesimanje, olulula lokufunda izisekelo ze-SQL ngezahluko ezimfushane, imibuzo esebenzisanayo, kanye nomtapo wolwazi osebenzayo. Wenzelwe abaqalayo abafuna ukuqonda imiqondo eyinhloko ye-SQL ngokucacile futhi bakhe ukuzethemba ngamaphethini emibuzo asetshenziswa emhlabeni wangempela kuzo zonke izizindalwazi ezidumile.

Umhlahlandlela we-SQL ugxile emiqondweni ye-SQL ejwayelekile, esetshenziswa kabanzi esebenza ezinhlelweni eziningi zedathabheyisi, ikusiza ukuthi wakhe amakhono adlula kalula phakathi kwezindawo.

Kungakhathaliseki ukuthi umusha kuzizindalwazi noma uvuselela amakhono abalulekile omsebenzi noma izingxoxo, Umhlahlandlela we-SQL usiza ukuthi ufunde i-SQL isinyathelo ngesinyathelo ngaphandle kokukhungatheka.

Funda Ngokwenza
Umhlahlandlela we-SQL uhlanganisa izincazelo ezicacile nokuzijwayeza okusheshayo, ukukuqondisa kusukela ekuqondeni kuya ekukhumbuleni nasekusebenziseni.

Funda izahluko ezimfushane, ezigxile nezibonelo zangempela
Zijwayeze imiqondo ngemibuzo esebenzisanayo
Sebenzisa ireferensi ye-SQL eyakhelwe ngaphakathi ukuze uthole ukubheka okusheshayo
Bhukha izihloko ezibalulekile bese uziphinda uzivakashele noma nini

Umhlahlandlela — Izisekelo ze-SQL
Landela ikharikhulamu ehlelwe ngokucophelela eyakha kusukela ezisekelo kuya kumaphethini e-SQL asetshenziswa njalo. Imiqondo nezibonelo ziyasebenza kuzo zonke izizindalwazi ezisetshenziswa kabanzi, kufaka phakathi i-MySQL, i-PostgreSQL, i-SQLite, i-Oracle, i-SQL Server, kanye ne-MariaDB.
Imibuzo: KHETHA, DISTINCT, UMKHAWULO
Ukuhlunga: LAPHO, FUTHI, NOMA, NGOKUPHAKATHI, NGITHANDA
Ukuhlunga nokuqoqa: ODA NGO, IQEMBU NGO, NGOKUNE-HAVING
Ukuhlanganiswa: COUNT, SUM, AVG, MIN, MAX
Ukujoyina: INKINGA, KWESOKUNXELE, KWESOKUDLA ngamaphethini okuhlanganisa asebenzayo
Ukubumba idatha: IKHASI, I-COALESCE, Ukuphathwa kwe-NULL
Izisekelo ezithuthukisiwe: Imibuzo engezansi, ama-CTE, i-UNION
Imiqondo ye-DDL kanye ne-DML: DALA ITHEBHULE, FAKA, BUYISA, SUSA (imiqondo namaphethini avamile)
Isahluko ngasinye sigxile ekusetshenzisweni kwe-SQL okusebenzayo kanye nemibono eyinhloko eyabelwana ngayo kuzo zonke izinhlelo zesizindalwazi, ngaphandle kobunzima obungadingekile noma imininingwane ethile yomthengisi.

Imibuzo — Prakthiza ngezincazelo
Qinisekisa ukufunda ngemibuzo emifushane, egxile eyenzelwe ukuhlola kokubili i-syntax kanye nokucabanga.

Izincazelo ezicacile ngemva kombuzo ngamunye
Iziqeshana ze-SQL ezingokoqobo kanye nezimo zemibuzo yansuku zonke
Ukugeleza okuqhubekayo okushelelayo ukuze ugcine umfutho wokufunda
Ukulandelela inqubekela phambili ukukhombisa lokho okufundile nokuthi yini elandelayo

Ireferensi — Ukubheka Okusheshayo kwe-SQL
Ireferensi ye-SQL emfushane, ehlelwe kahle emboza izihloko ze-SQL ezisetshenziswa njalo kanye namaphethini e-syntax atholakala kakhulu ezindaweni ze-MySQL, PostgreSQL, SQLite, Oracle, SQL Server, kanye ne-MariaDB. Ilungele izikhumbuzi ezisheshayo ngenkathi ufunda noma ubukeza.

Amabhukhimakhi kanye Nenqubekela phambili
Bhukhimakhi izahluko nezihloko zereferensi
Landelela inqubekela phambili yesifundo kanye nokuqedwa kwemibuzo
Thola amabheji njengoba uqedela izifundo ezibalulekile

Ubani LoAbafundi bafunda izisekelo ze-SQL
Onjiniyela bavuselela amakhono e-SQL ayisisekelo
Abahlaziyi abaqhuba imibuzo nemibono
Noma ubani olungiselela izingxoxo ze-SQL noma ukuhlolwa okubandakanya i-MySQL, PostgreSQL, SQLite, Oracle, SQL Server, noma i-MariaDB

Ubumfihlo Nokufinyelela
Akukho akhawunti edingekayo
Akukho ukungena ngemvume noma ukungena kwangaphandle
Akukho ukulandelela
Konke kumahhala. Landa futhi uthole konke okuqukethwe ngokushesha.

Landa Umhlahlandlela we-SQL bese uqala ukufunda i-SQL ngokushesha.

Yini entsha

First release.