Iingxelo SQL Basic

SQL umgangatho wavunywa ngo 1992 kwaye isasetyenziswa nanamhlanje. Ukuba uye waba benchmark for ezininzi iinkqubo zolawulo ledatha. Kakade ke, abanye abavelisi basebenzisa nokutyhilwa zabo umgangatho. Kodwa nayiphi na inkqubo, kusekho iinkalo eziphambili - Iingxelo SQL.

isingeniso

Ukusebenzisa iingxelo SQL kwi database kwenzeka iitafile zolawulo values namalungiselelo abo buhlolwe ngokubanzi kunye nokubonisa. Basimisela iseti amagama athile, apho le nkqubo uyakwazi into yokwenza data.

Chaza iindidi eziliqela iingxelo SQL:

• Inkcazo yezinto database;
• izakhi amanani;
• nokhuselo kunye nolawulo;
• parameters session;
• Ulwazi malunga kwisiseko;
• SQL static;
• SQL linamandla.

iingxelo SQL ukuze zisetyenziswe data

Olu didi lubandakanya i amagama apho uyakwazi ukulawula ukufakwa lamaxabiso ledatha.

INSERT. Faka umqolo kwi kwetafise ekhoyo. Ingasetyenziswa njenge ixabiso esinye okanye ezininzi, echazwa imeko ethile. Umzekelo:

INSERT LIBE

igama letheyibhile (kwikholam 1 igama, igama kumhlathi 2)

ZENTSULUNGEKO (ixabiso 1 ixabiso 2).

Ukusebenzisa i umsebenzisi ingxelo SQL INSERT kunye neenqobo abaninzi, sebenzisa lwesivakalisi zilandelayo:

INSERT LIBE

igama 1 itheyibhile (igama kwikholam 1, umhlathi igama 2)

KHETHA ligama lomhlathi 1, igama kumhlathi 2

FROM igama letheyibhile 2

APHO Igama 2.imya column itheyibhile 1> 2

Le umbuzo kukhetha konke idatha kuLuhlu 2, engaphezulu kwe-2 ukuze kwikholam 1 uze uyincamathelise onke kowokuqala.

UPDATE. Nanjengoko igama layo lixela, le ngxelo ihlaziya data SQL umbuzo kwi tafile ezikhoyo qho ethile.

umzekelo:

UPDATE igama letheyibhile 1

Igama column SET = 2 "Basil"

APHO igama letheyibhile column 1.imya 1 = 1

Esi sakhiwo fill ixabiso Basil yonke imiqolo ezifezekisayo inombolo 1 kwikholam yokuqala.

SUSA. Lisusa data evela etafileni. Unga khankanya nayiphi na imeko okanye ukususa yonke imiqolo.

Sula igama letheyibhile

APHO column Igama tablitsy.imya 1 = 1

Le umbuzo ngasentla kuzakucima wonke umbhalo kwi-database kunye ixabiso enye kwikholam yokuqala. Nantsi indlela uyakwazi ukususa le theyibhile lonke:

Sula igama letheyibhile.

Okulandelayo kuyimfuneko ukuxelela malunga ingxelo KHETHA. Nguye yenye yezinto ezibalulekileyo, ngoko ke kuya kufuneka achithe isahluko eyahlukileyo.

mazwi KHETHA

Eyona njongo ye KHETHA - ukukhethwa ze data ngokweemeko ezithile. Isiphumo umsebenzi wakhe isoloko itafile entsha data ekhethiweyo. MS umqhubi SQL KHETHA ingasetyenziswa ubunzima izicelo ezahlukeneyo. Ngoko ke, kunye nayo, usenokufunda amanye amagama ezinxulumeneyo.

Ukukhetha yonke uphawu data "*" lisetyenziswa kwi itafile ethile.

KHETHA *

FROM igama letheyibhile 1

Isiphumo sale lombuzo iya kuba ikopi ngqo kwetafile 1.

Apha ndindi APHO imeko encothula ukusuka Itheyibhile 1, onke amaxabiso ngaphezu 2 kwikholam 1.

KHETHA *

FROM igama letheyibhile 1

APHO Igama 1.imya column itheyibhile 1> 2

Ungakhankanya kukhetho ukuba kuphela izintlu ezithile ezifunekayo.

KHETHA igama letheyibhile 1.imya kwikholam 1

FROM igama letheyibhile 1

Isiphumo sale lombuzo bonke imigca kunye amaxabiso lomxholo 1. Ukusebenzisa abasebenzi MS SQL uyakwazi ukwenza itheyibhile yayo, ngexesha lokuthath'indawo, ukubala kunye wokusebenzisa amaxabiso athile.

KHETHA

igama letheyibhile 1.imya kwikholam 1

igama letheyibhile 1.imya kumhlathi 2

igama letheyibhile column 1.imya 3

«=» AS EQ

igama letheyibhile 1.imya kumhlathi 2 kwetafile igama * column 1.imya 3 AS nesimva

FROM igama letheyibhile 1

Le umbuzo ebonakala esimbaxa ithengiseka onke amaxabiso akuluHlu 1, uze emva koko idala ikholam entsha kunye EQ nesimva. Kuqala ungena uphawu "+", kwikholam yeenkcukacha wesibini imveliso 2 no 3. Esi siphumo angamelwa njenge itafile, ngokuba ukuqonda ukuba isebenza njani;

kwikholam 1	kwikholam 2	kumhlathi 3	EQ	nesimva
Igama Product 1	10	50	+	500
Igama Product 2	15	100	+	1500

Ukuba usebenzisa ingxelo KHETHA, ungenza ngokukhawuleza uchitha odola data kwi naziphi na isizathu. Isebenzisa igama UKUZE BY.

KHETHA

igama letheyibhile 1.imya kwikholam 1

igama letheyibhile 1.imya kumhlathi 2

igama letheyibhile column 1.imya 3

FROM igama letheyibhile 1

UMYALELO BY igama kumhlathi 2

Le theyibhile sisiphumo kukhangela ngolu hlobo:

kwikholam 1	kwikholam 2	kumhlathi 3
1	1	54
3	2	12
7	3	100
2	5	1

Oko kukuthi, yonke imigca olufakwe ngendlela yokuba kumhlathi 2 amaxabiso zinyuka.

Data kwakhona zingafumaneka iitafile ezininzi. Ecacileyo, kufuneka uqale ukucinga ukuba amabini, abanye kule database:

Uluhlu "Abasebenzi"

inombolo	igama	isibongo
1	Vasya	Vasin
2	Petya	Petin

Uluhlu "Salary"

inombolo	izinga	udumo
1	1	10000
2	0.5	3500

Ngoku kufuneka, ezifana onxulumanisa amacwecwe amabini ukufumana amaxabiso eqhelekileyo. Ukusebenzisa iingxelo SQL esisiseko oko kwenziwa ngolu hlobo lulandelayo:

KHETHA

Sotrudniki.Nomer

Sotrudniki.Imya

Zarplata.Stavka

Zarplata.Nachisleno

FROM Abasebenzi Salary

APHO Sotrudniki.Nomer = Zarplata.Nomer

Kukho zathatha iitafile ezimbini ezahlukeneyo amaxabiso, simanyene ngenani. Isiphumo iseti zilandelayo data:

inombolo	igama	izinga	udumo
1	Vasya	1	10000
2	Petya	0.5	3500

Kancinane ngakumbi malunga KHETHA. Ukusebenzisa imisebenzi aggregate

Enye iingxelo ezisisiseko SQL KHETHA unako ukuvelisa ezinye izibalo kwisampulu. Ukuze wenze oku, usebenzisa imisebenzi ethile kunye neefomula.

Ngokomzekelo, ukuze ufumane inani kweerekhodi etafileni "Abaqeshwa", kufuneka usebenzise umbuzo:

COUNT KHETHA (*) AS N

FROM Abasebenzi

Umphumo iya kuba itafile elinomhlathi omnye kunye nexabiso.

N

2

msebenzi kusetyenziswa imibuzo ukuba uakubala isiphumo sokudibanisa, ubukhulu kunye neenqobo ubuncinane, kwaye umlinganiselo. Ukuze wenze oku, amagama asetyenziswa SUM, MAX, MIN, AVG.

Umzekelo, ukuba kuyimfuneko ukubamba isampulu sele eyaziwa "lomvuzo" itheyibhile:

inombolo	izinga	udumo
1	1	10000
2	0.5	3500

Ungenza isicelo isicelo esinjalo kwaye bona okwenzekayo:

KHETHA

SUM (Zarplata.Nachisleno) AS nesimva

MAX (Zarplata.Nachisleno) AS MAX

MIN (Zarplata.Nachisleno) AS MIN

AVG (Zarplata.Nachisleno) AS SRED

FROM Salary

Le theyibhile lokugqibela iza kuba ngolu hlobo lulandelayo:

nesimva	MAX	MIN	SRED
13500	10000	3500	6750

Yiloo ndlela, uyakwazi ukukhetha database amaxabiso afanelekileyo kubhabho ukuba enze ubalo imisebenzi eyahlukeneyo.

Union, kuhlangana kunye umahluko

Dibanisa imibuzo multiple kwi SQL

KHETHA Sotrudniki.Imya

FROM Abasebenzi

APHO Sotrudniki.Nomer = 1

UNION

KHETHA Sotrudniki.Imya

FROM Abasebenzi Salary

APHO Zarplata.Nomer = 1

Kufuneka kukhunjulwa ukuba kule theyibhile umbutho kufuneka ibe ingahambelani. Oko kukuthi, ukuba inani elifanayo columns.

Le syntax ingxelo KHETHA kunye nenkqubo processing

Into yokuqala KHETHA imisela ndawo apho kuya kuthatha i data. Ukuze wenze oku, sebenzisa igama FROM. Xa ingakhankanywanga, yintoni ukuze ukhethe.

Unako ke thaca lo mgaqo SQL apho. Ngoncedo lwe KHETHA enqamleza kumqolo ngamnye etafileni kwaye sijonga iinkcukacha ukuze kuthotyelwe imeko.

Ukuba Isicelo iqela, ngoko kukho eliCebisayo lwamaxabiso ezi parameters.

Abanini ukuthelekisa data

Baye iintlobo eziliqela. Xa SQL Umqhubi uthelekiso ungavavanya iintlobo ezahlukeneyo lwamaxabiso.

• "=". Kubonisa, njengoko unokuthekelela, yokulingana mabinzana mabini. Ngokomzekelo, ukuba sele isetyenziswe kule mizekelo ingasentla - APHO Zarplata.Nomer = 1.

• ">". Greater-ngaphezu mqondiso. Ukuba ixabiso kwicala lasekhohlo binzana mkhulu ngoko TRUE ubhalo ibuyiswa nemeko uzalisekisiwe.

• "<". Uphawu lobuncinci. Reverse umsebenzi wangaphambili.

• Iimpawu ze "<=" kunye "> =". Yohluka ukusuka abaqhubi ilula kwaye ngaphantsi kukuba kunye operands alinganayo imeko yinyaniso.

• "<>". Andikhathali. Imeko ithathwa TRUE, ukuba omnye kuphela we- akalingani kwenye. Yena ulichaza enye ngaphezulu - "! =".

njengaleyo

Guqulela le igama kunokuba kuba 'efanayo. " KANYE operator SQL isetyenziswa malunga kumgaqo - likwaqhuba umbuzo kwi template. Oko kukuthi, kukuvumela ukwandisa data isampuli evela kuvimba kusetyenziswa amabinzana rhoqo.

Umzekelo, ukuba ubeka umsebenzi onjalo: ukusuka kwisiseko "abasebenzi" sele kwaziwa ukuba bonke abantu ogama lakhe iphela nge "I". Emva koko isicelo yenziwe ngolu hlobo lulandelayo:

KHETHA *

FROM Abasebenzi

APHO Igama KANYE `% I`ll

uphawu lwepesenti kulo mzekelo uthetha imaski, oko kukuthi, nawuphi na umsebenzisi, kunye nenani labo. Kwaye kule ncwadi, "Mna» SQL umisela ukuba ubhalo lokugqibela ibe ngaloo ndlela.

YETYALA

Le Umncedisi Ingxelo SQL kuyinto ukuqaliswa kwe imibuzo okhetha enye kozinikiweyo. Oku kufana ingxelo yotshintsho ngeelwimi ezininzi kweenkqubo. Ingxelo ITYALA kwi SQL wenza isenzo kwiimeko eziliqela.

Umzekelo, ukhetha itafile "umvuzo" ubuninzi kunye nemilinganiselo ubuncinane.

inombolo	izinga	udumo
1	1	10000
2	0.5	3500

Emva koko isicelo yenziwe ngolu hlobo lulandelayo:

KHETHA *

FROM Salary

APHO ITYALA XA KHETHA MAX (imali) KUDALA Maximum

XA KHETHA MIN (imali) KUDALA Ubuncinane

ISIPHELO ngenxa

kwi "imali" ikholam kule meko, inkqubo ukhangela ixabiso kwelona qondo. Emva koko, usebenzisa intsimi END wadalwa "zizonke", nto leyo uzakufakwa kwi "ubuninzi" okanye "ubuncinane" ngokuxhomekeke ngesiphumo imeko.

Ngendlela, xa SQL kukho uhlobo compact ngakumbi ITYALA - COALESCE.

definition data

Le mbono ikuvumela ukuphumeza iintlobo iitafile ukutshintsha - dala, susa, guqula kancinane, baze basebenze kunye nezalathiso.

Eyokuqala, nto leyo into ekufaneleke ukuba siyicinge - Dala ITHEYIBHILE. Uyayenza into eyenye kunokuba ekudaleni itafile. Ukuba nje uchwetheza MASIDALE ULUHLU umbuzo, akukho nto iza kwenzeka, kuba ufuna ukucacisa iparameters ezininzi ngakumbi.

Umzekelo, ukwenza itheyibhile eqhelekileyo "Abasebenzi" ufuna ukusebenzisa umyalelo:

Dala ITHEYIBHILE Abasebenzi

(Inombolo yesazisi (10) NOT byte

Igama varchar (50) NOT byte

Igama lokugqibela varchar (50) NOT byte)

Kwesi sicelo, kwindawo yegama echazwe nangoko amagama kunye neentlobo zazo, kwakunye nokuba kunokuba byte.

YIWA ITHEYIBHILE

Yenza umsebenzi olula - ekususeni itafile utshilo. Kuye ukhetho ongezelelweyo xa xona. It lubamba imposiso xa ususa, ukuba ayisekho itafile efunekayo. Umzekelo ukusebenzisa:

YIWA ITHEYIBHILE Employees IF xona.

Dala ISALATHISO

E SQL, kukho inkqubo indices, leyo ivumela unikezelo oluikhawuleza kakhulu data. Ngokwesiqhelo, le ikhonkco obalatha ikholam ethile. Yenza isalathisi ingaba isicelo esilula:

Dala ISALATHISO nazvanie_indeksa

ON nazvanie_tablitsy (nazvanie_stolbtsa)

Sebenzisa le ngxelo e T-SQL, Oracle, PL SQL kunye ezininzi ubugcisa nezinye iinguqulelo.

Alter ITHEYIBHILE

operator esebenza kakhulu kunye iinketho ezininzi. Ngokubanzi, utshintsho uvelisa inkcazelo isakhiwo kunye neetheyibhile ulwabiwo. Operator isetyenziswa Oracle SQL, Postgres, kunye nabanye abaninzi.

Reference ngoku ziya kunikwa iinketho ezahlukeneyo usebenzisa Alter ITHEYIBHILE.

• ADD. Uwugcinayo Ukongeza bomhlathi kwitheyibhile. Syntax naye oku: ukutshintsha ULUHLU ADD nazvanie_tablitsy nazvanie_stolbtsa tip_hranimyh_dannyh. Ingaba unayo i parameter UKUBA ukho, leyo abayithintelayo impazamo xa kukho ikholam sele idale;

• YIWA. Osusa column. IF ikhona nayo igqityiwe, nto leyo eza kuvelisa impazamo esithi ukuba ayisekho kwikholam kuceliwe;

• Tshintsha. Isetyenziswa ukuthiya ngokutsha igama ecacisiwe. Umzekelo kwedatha: ukutshintsha ULUHLU Tshintsha nazvanie_tablitsy OldName new_name;

• Lungisa. Lo myalelo iza kutshintsha uhlobo ikholam ethile kunye iimpawu ezongezelelweyo. Kwaye isetyenziswa ngolu hlobo: ukutshintsha ULUHLU guqula nazvanie_tablitsy nazvanie_stolbtsa datatype izibaluli;

Dala Qala

Xa SQL, kukho loo nto ibe ingcamango. Ngamafutshane, le uhlobo itafile enesiqhamo le data. Oku abunjwe ngenxa kwisampula esebenzisa ulwimi SQL KHETHA statement. Izimvo unganciphisa ukufikelela kuvimba ukuzimela kubo, ukuba indawo amagama kwikholam lokwenene.

Inkqubo edala lwenzeka yi umbuzo elula:

Dala JONGA Igama imboniselo AS Khetha * igama letheyibhile

Komculo ingathatha ndawo database wonke ngokubanzi, kwaye imeko ethile.

A kancinci malunga neempawu

Xa SQL imibuzo basoloko besebenzisa imisebenzi eyakhelwe-ngaphakathi ezahlukeneyo ezikuvumela ukuba basebenzisane data eyiguqula kubhabho. Iyafuna bewagqala, njengoko lukwa yinxalenye ebalulekileyo kolwimi.

• COUNT. Ikhupha ubala imiqolo okanye amangeno itafile ethile. Njengoko kukho khetho, ungakhankanya ligama lomhlathi, ngoko ke idatha uya kuhluthwa kwanoko anako. COUNT * KHETHA FROM Abasebenzi;

• AVG. Olu phawu usebenza kuphela izintlu kunye data yamanani. ngenxa yaso ukumiselwa imin lokubala eliguqukayo onke amaxabiso;

• MIN ne MAX. Le misebenzi ziye zasetyenziswa kweli nqaku. Bona ukuchaza ubukhulu kunye neenqobo ubuncinane kumhlathi wathi;

• SUM. Yinto elula - umsebenzi ubala udibaniso lwamaxabiso phantsi komxholo. Oku kusetyenziswa kuphela uhlobo data yamanani. Ukongeza isicelo i parameter enomahluko, ziya kongezelelwa kuphela kumaxabiso ezizodwa;

• UMJIKELO. Umsebenzi usondelisa amanani fraction wokugqibela. Le syntax esetyenziswa yi igama kwikholam kunye nenani needesimali;

• LEN. A umsebenzi elula ubala ubude mhlathi. Umphumo iya kuba itafile entsha ebonisa inani loonobumba;

• NOW. Le igama isetyenziselwa ukubala umhla wangoku kunye nexesha.

abaqhubi ezongezelelweyo

imizekelo emininzi iingxelo SQL zizinto amagama ukuba enze imisebenzi ezincinane, kodwa kunjalo lula kakhulu isampuli okanye umsebenzi ledatha.

• AS. Oku kusetyenziswa xa ufuna ukwenza amalungiselelo abangaboniyo umphumo sabele igama elikhankanyiweyo ukufumana itafile.

• PHAKATHI. Isixhobo Ukugunda kakhulu ukukhiwa. Oku kubonisa indlela umqolo wamaxabiso, kuquka imfuneko ukuze ufumane iinkcukacha. ufake i parameter lifumana ukusuka kuluhlu inombolo iyasetyenziswa.

• NOT. Umqhubi unika malunga eli binzana.

• Ungalinciphisa libe ngamalungu asibhozo. Isusa data evela uthe kwisiseko nesabelo. Ezahlukileyo kwezo nabatyalimali ukubuyisa data emva ukusetyenziswa kwayo akunakwenzeka. Kubangel 'umdla ukwazi ukuba ukuphunyezwa igama enikwe SQL ahlukileyo kunokuba ukutolika ezahlukeneyo. Ngoko ke ngaphambi kokuba uzame ukusebenzisa Ungalinciphisa libe ngamalungu asibhozo, uqhelane ngakumbi ulwazi yangasemva.

• LIMITED. Icwangcisa inani imigca kwimveliso. Le peculiarity ye umqhubi ukuba isoloko ibekwe ekupheleni. Lithatha ayisosinyanzelo kwaye omnye parameter optional. Eyokuqala ibonisa ukuba banemiqolo emingaphi na idata ekhethiweyo ukubonisa. Ke ukuba yesibini, ngoko umqhubi isebenza zombini uluhlu lwamaxabiso.

• UNION. umsebenzisi-friendly operator kakhulu ukudibanisa imibuzo ezininzi. Uye kakade phakathi imizekelo oku kweli nqaku. Uyakwazi ukubonisa imiqolo ukusuka kwizintlu ezininzi, UNION yokudibanisa ukuze ukusetyenziswa lula ngakumbi. Syntax naye oku: KHETHA column_name kwitafile UNION KHETHA FROM itheyibhile imya_drugogo_stolbtsa imya_drugoy. Isiphumo isishwankathelo kwiimfuno united itafile.

• Iqhosha. Eliguqulelwa ngokuthi "iqhosha." Eneneni, ukuba isigama enjalo esetyenziswa iimathiriyeli zesalalhiso. Yena into ebonakalisayo eyahlukileyo emgceni. Lusetyenziswa, njengoko umthetho, xa kudalwa itafile ukubonisa intsimi eza kuba kuyo.

• Default. Kanye njengokuba umqhubi elidlulileyo, esetyenziswa ekuphunyezweni ekudaleni umbuzo. Le ichaza ixabiso elisisiseko, oya kuzaliswa endle xa wadala.

A tips ezimbalwa ukuphuhlisa iqonga asebenze SQL

1. Byte. Beginners hayi badwelisi benkqubo kuphela ekulungiseleleni izicelo basoloko belibala kubukho amaxabiso byte. Ngenxa yoko, ikhowudi impazamo enyakazelayo kulo, apho kunzima ukulandelela kwinkqubo USB. Ngoko ke, xa kudalwa itafile, amaxabiso isampuli okanye zibalwe ngokutsha kufuneka ziyema zicinge, nokuba isahlakalo byte kuthathelwa ingqalelo kule ndawo umbuzo.

2. Memory. Kweli phepha thina baboniswa iqela lemisebenzi, ekwaziyo ukwenza imisebenzi ethile. Kuphuhliso yeqokobhe ukusebenza kunye database, unako 'ukudlula' ukubalwa amabinzana ezilula kwinkqubo ledatha. Kwezinye iimeko, oku kunika inkxaso ebalulekileyo yokusebenza.

3. Izithintelo. Ukuba ufuna ukufumana evela kuvimba kunye amawaka imikrozo emibini kuphela, kuyimfuneko ukusebenzisa baqhubi njenge LIMITED okanye TOP. Akukho mfuneko ukuvumbulula ungeno lwe data esebenzisa iqokobhe zophuhliso lolwimi.

4. Connect. Kwakufika data evela iitafile eziliqela, badwelisi benkqubo ezininzi ziya kuqalisa ukunciphisa ndawonye kwimvulophu memory ithetha. Kodwa kutheni? Ngapha koko, ungenza isicelo apho konke kuya kuba khona. Akuyomfuneko ukuba ubhale ikhowudi kanye uzibekele memory ezongezelelweyo kwinkqubo.

5. Ukuhlela. Ukuba unako ukusebenzisa ngummiselo isicelo, oko kukuthi, imikhosi DBMS, kuyimfuneko ukuyisebenzisa. Oku kuya konga kakhulu kwizibonelelo xa inkqubo okanye inkonzo.

6. izicelo ezininzi. Ukuba kufuneka ufake eninzi iirekhodi ngokulandelelana, ngoko noun kufuneka ucinge ipakethe yeenkcukacha ifakiwe isicelo enye. Oku kuya kwandisa ukusebenza kwenkqubo yonke.

7. Ukufakwa ngenyameko lwe data. Phambi ukuzoba up isakhiwo isiseko kufuneka ucinge ngendlela nokuba inani enjalo iitafile kunye namasimi kuyimfuneko. Mhlawumbi kukho indlela ukuhlanganisa kubo, okanye bayeke ezinye. Amaxesha amaninzi, badwelisi benkqubo basebenzisa isixa ngokugqithiseleyo data esetyenziswa ndawo, angoni.

8. Types. Ukugcina isithuba kunye nezibonelelo kufuneka ukuba ziyithathele ingqalelo iintlobo ze data ezisetyenzisiweyo. Ukuba uyakwazi ukuthatha oxhaphaza ngaphantsi "heavy 'ukuba uhlobo inkumbulo, kufuneka ukusebenzisa igama lakhe. Umzekelo, Ukuba kwakusazeka ukuba lo mhlaba lixabiso lenani ayisayi kudlula 255, kutheni ukusetyenziswa kwe-4-byte INT, ukuba kukho TINYINT 1 Byte.

isiphelo

Xa ndiqukumbela, kufanele kuqatshelwe ukuba ulwimi yakhiwe imibuzo SQL ngoku kusetyenziswa phantse yonke indawo - websites, iinkonzo web, isoftwe ye-desktop, izicelo mobile. Ngoko, ulwazi SQL kuya kunceda onke amacandelo yophuhliso.

Noko ke, ukuguqulwa zomthonyama standard ulwimi ngamanye amaxesha kwahluka enye kwenye. Umzekelo, PL abanini SQL abe kwezivakalisi eyahlukileyo kunokuba Kumncedisi we SQL. Ngoko ke ngaphambi kokuba uqale ukuphuhlisa nobu buchwepheshe, kuyimfuneko ukuba uqhelane nayo sikhokelo.

Xa nabalingani elizayo, nenokuthi Zizigqithile usebenziso SQL kunye nokusebenza, akuthandeki ukuba avele, ngoko lo umda kakhulu zinendawo elithembisayo nayiphi Ndingumqondisi.