Kodi kulemba SQL-mafunso - zofunikila Zitsanzo

Zonse aliyense wa ife loyang'anizana ndi amagwiritsa zosiyanasiyana zinasokoneza makompyuta. Pamene ife tisankha imelo adilesi, ife akugwira ntchito ndi Nawonso achichepere. Nawonso achichepere pogwiritsa ntchito kufufuza, magombe kwa kusungiramo deta kasitomala, etc.

Koma ngakhale zones za Nawonso achichepere, kuphatikizapo ambiri mapulogalamu machitidwe kutukula zambiri "mawanga woyera" chifukwa kutanthauzira zosiyanasiyana za mawu omwewo. Ife kupereka tanthauzo mwachidule mfundo yaikulu zinasokoneza makompyuta a SQL kuganizira. Apitirizebe

Nawonso achichepere - wapamwamba kapena owona kwa kasungidwe analamula deta nyumba ndipo ubwenzi wawo. Nthawi zambiri, Nawonso achichepere imatchedwa ndi kasamalidwe dongosolo Nawonso achichepere (DBMS). Nawonso achichepere - izo zangokhala zapamwamba wa uthenga mtundu yeniyeni ndipo angathe kugwira ntchito ndi zinasokoneza makompyuta osiyana.

Table - kulingalira chikwatu imene zikalata zasungidwa, m'magulumagulu malinga ndi magawo ena, monga mndandanda wa malamulo kwa mwezi watha. Izi tebulo mu kompyuta Nawonso achichepere. A tebulo osiyana ali yake dzina lapadera.

Data Mtundu - mtundu wa mudziwe analola kusungidwa mu ndime imodzi kapena mzere. Kungakhale yeniyeni nambala kapena lemba mtundu.

Mzati ndi mzere - tonse ntchito ndi spreadsheets, amene alipo mu mizere ndi mizati. Aliyense Nawonso achichepere ubale ntchito ndi matebulo njira yomweyo. Zingwe amatchedwa mbiri.

Kiyi chachikulu - mzera uliwonse mwina mizati chimodzi kapena zingapo pa chizindikiritso yake yapadera. No chinsinsi chachikulu zovuta kusintha, kusintha ndi kuchotsa mizere zogwirizana.

SQL ndi chiyani?

chilankhulo kafufuzidwe SQL (English Choyesera kafufuzidwe Language -. Structured kafufuzidwe Language) udaikidwa yekha ntchito ndi zinasokoneza makompyuta ndipo panopa mfundo zinasokoneza makompyuta onse otchuka. The malembedwe chinenero wapangidwa ochepa ntchito ndi kophweka. Koma ngakhale kuphweka akuoneka, timatha chilengedwe cha mafunso SQL kwa ntchito zovuta ndi Nawonso achichepere a kukula kulikonse.

Popeza 1992, pali muyezo wamba, wotchedwa ANSI SQL. Iwo amasonyeza malembedwe zikuluzikulu ndi ntchito za ntchito ndi imayendetsedwa ndi onse atsogoleri DBMS msika, monga masomphenya ndi Microsoft a SQL yawonongeka. Taganizirani mbali zonse za chinenero m'nkhani yochepa n'zosathekadi, kotero ife tikambirane mwachidule okha mafunso zofunika SQL. Zimasonyeza kuphweka ndi mbali ya chinenero:

• kulenga zinasokoneza makompyuta ndi magome;
• deta kusankha;
• Powonjezera zolemba;
• kusinthidwa ndi kufufutidwa zambiri.

Mitundu SQL Data

mizati onse tebulo Nawonso achichepere kusunga deta wofanana. mu SQL mitundu deta ndi chimodzi mwa zilankhulo zina mapulogalamu.

mtundu deta	mafotokozedwe
Int	integers
ENIENI	Akuyandama manambala mfundo
LEMBA	Khalidwe chingwe kutalika variable
DATE	SQL kafufuzidwe "tsiku" zosiyanasiyana akamagwiritsa
TIME	nthawi
Char	zingwe Text kutalika amodzi

Pangani matebulo ndi zinasokoneza makompyuta

Pangani zinasokoneza makompyuta latsopano, matebulo ndi mafunso ena SQL Pali njira ziwiri:

• mawu SQL mwa kutonthoza Nawonso achichepere
• Kugwiritsa zokambirana zida Administration, gawo la makina Nawonso achichepere.

A latsopano Nawonso achichepere woyendetsa Pangani Nawonso achichepere ; . Monga mukuonera, malembedwe ndi yosavuta zambiri.

Magome mkati Nawonso achichepere kulenga kulenga MITU mawu ndi magawo zotsatirazi:

• dzina tebulo
• maina ndi deta mitundu ya mizati

Mwachitsanzo, kulenga chofunika tebulo ndi mizati zotsatirazi:

Danga	mafotokozedwe
commodity_id	mankhwala ID
vendor_id	Bizinezi ID (mavenda Ofunika kunja tebulo)
commodity_name	dzina mankhwala
commodity_price	mtengo wa
commodity_desc	mafotokozedwe

Jambulani tebulo:

Pangani MITU chofunika

(Commodity_id Char (15) OSATI NULL,

vendor_id Char (15) OSATI NULL,

commodity_name Char (254) NULL,

commodity_price DECIMAL (8,2) NULL,

commodity_desc VARCHAR (1000) NULL);

Tebulo lili mizati isanu. Pambuyo dzina la mtundu wa mizati deta anasiyanitsidwa ndi mipatuliro. Mtengo ndime kukhulupirira mfundo null (NULL) kapena ayenera kudzazidwa mu (OSATI NULL), ndipo akufunitsitsa jambulani tebulo.

Zitsanzo deta ku gome

deta zitsanzo zosankhidwazi woyendetsa - kwambiri amagwiritsidwa ntchito mafunso SQL. Kuti mudziwe zambiri muyenera mwachindunji kuti tikufuna kusankha kwa tebulo. Poyamba chitsanzo losavuta:

Sankhani commodity_name KWA chofunika

Pambuyo mawu Sankhani amasonyeza dzina la ndime infomeshoni, koma limatchula tebulo.

Zotsatira kafufuzidwe adzakhala onse mizere tebulo ndi Commodity_name makhalidwe ndondomeko imene iwo adalowa Nawonso achichepere ndi i.e. popanda kusanja iliyonse. Bungwe zotsatira ntchito optional woyendetsa DONGOSOLO NDI.

QUERY pa minda angapo lembani iwo ankasiyana mipatuliro monga zotsatirazi:

Sankhani commodity_id, commodity_name, commodity_price KWA chofunika

N'zotheka kuti chifukwa cha phindu kafufuzidwe chingwe cha mizati onse. Chifukwa chaichi, chizindikiro "*":

Sankhani * KWA chofunika

• SANKHANI Komanso amathandiza:
• deta mtundu (DONGOSOLO mwamawu)
• Kusankha monga zikhalidwe (KUMENE)
• Grouping akuti (GULU NDI)

kuwonjezera mzere

Kuwonjezera mizere tebulo ntchito mfundo SQL ndi mawu Ikani. Kuwonjezera akhoza kukhala mu njira zitatu:

• kuwonjezera malire atsopano lonse;
• a mzere;
• Zotsatira kafufuzidwe.

Kuwonjezera mzere wonse, ayenera mwachindunji tebulo dzina ndi mfundo za mizati (m'minda) mzere wa latsopano. Pano pali chitsanzo:

Ikani MU MFUNDO chofunika ( '106', '50', 'koka-Cola, ' 1,68 ',' Palibe Alcogol,)

Mwachitsanzo anati mankhwala atsopano ku gome. Kutengera zinthu mwachindunji pambuyo MFUNDO aliyense yachiwiri. Ngati palibe mtengo m'malo mwa ndime ya, m'pofunika mwachindunji NULL. mizati ali wodzazidwa ndi makhalidwe dongosolo mwachindunji polenga tebulo.

Pankhani ya kuwonjezera yekha gawo la chingwe ayenera motsimikizira mwachindunji dzina la ndime, monga mwa Chitsanzo:

Ikani MU chofunika (commodity_id, vendor_id, commodity_name)

MFUNDO ( '106', '50', 'koka-Cola, )

Ife anayambitsa yekha identifiers mankhwala, katundu ndi dzina lake, ndipo zina zonse za kuthengo pambali kanthu.

Powonjezera zotsatira kafufuzidwe

Kwenikweni, amaika ntchito kuwonjezera mzere, koma angagwiritsidwe ntchito kuwonjezera zotsatira Sankhani mawu.

kusintha deta

Kusintha mfundo m'minda Nawonso achichepere tebulo ayenera kugwiritsa ntchito mfundo LIPOTI. woyendetsa angagwiritsidwe ntchito m'njira ziwiri:

• Kusinthidwa mizere onse tebulo.
• Only kwa mzere winawake.

LIPOTI tichipeza zinthu zitatu:

• tebulo lomwe mukufuna kusintha;
• maina kumunda ndi makhalidwe awo latsopano;
• Zinthu kusintha mzere kusankha.

Tiyeni tione chitsanzo. Tiyeni tinene mankhwala ndi ID = 106 wasintha mtengo, kotero mzere uwu kusintha. Lembani mawu otsatirawa:

LIPOTI chofunika Ikani commodity_price = '3.2' KUMENE commodity_id = ' 106'

Ife analozera tebulo dzina, mu nkhani iyi, chofunika, umene kusinthidwa, ndiyeno pambuyo Anatipatsa - phindu latsopano la mzati ndi kupeza chinthu anakhumba, kutchula kumene anakhumba mtengo ID.

Kusintha chiwerengero cha mizati pambuyo mawu Ikani n'chakuti awiriawiri angapo ndime mtengo, ankasiyana mipatuliro. Onani chitsanzo chimene dzina ndi mtengo wa katundu ndi kusinthidwa:

LIPOTI chofunika Ikani commodity_name = 'Fanta' , commodity_price = '3.2' NANGA commodity_id = ' 106'

Kuchotsa mfundo mzati, mukhoza anapereka kwa NULL, ngati timatha kapangidwe ka tebulo. Kumbukirani kuti NULL - ichi ndi "ayi" mtengo, osati ziro monga lemba kapena manambala. Chotsani item kufotokoza:

LIPOTI chofunika Ikani commodity_desc = NULL KUMENE commodity_id = ' 106'

Kuchotsa mizere

zopempha SQL kuchotsa mizere tebulo zimagwiridwa Chotsani woyendetsa. Pali njira ziwiri ntchito:

• Table zichotsedwa mizere ena;
• kuchotsedwa mizere onse tebulo.

CHITSANZO kuchotsa mzere umodzi wa tebulo:

Chotsani KWA chofunika KUMENE commodity_id = '106'

Pambuyo Chotsani KWA akufotokozera tebulo dzina limene kuchotsa mizere. KUMENE woyendetsa zikuphatikizapo chikhalidwe umene mzere adzakhala akanasankhidwa kufufutidwa. Mu chitsanzo ife kuchotsa mzere mankhwala ndi ID = 106. KUMENE zimasonyeza zofunika kwambiri chifukwa apambane privedt woyendetsa kuchotsa mizere onse tebulo. Zimenezi zikukhudza kusintha makhalidwe kumunda.

Mawu Chotsani silitchula maina ndime, ndipo pambuyo-m'nkhaniyi. Iye kwathunthu amachotsa mzere ndi kuchotsa ndi ndime wosakwatiwa, sangatero.

Kugwiritsa SQL mu Microsoft Access

Microsoft Access ndi amagwiritsidwa ntchito interactively kulenga spreadsheet, Nawonso achichepere, kusintha kasamalidwe, ndi kusanthula deta mu Nawonso achichepere ndi kuti litsatira mafunso SQL Access kudzera yabwino zokambirana kafufuzidwe anaumanga (akafufuzidwe Mlengi), ntchito zimene mungathe kumanga ndi kudzapereka mawu SQL yomweyo Kuvuta iliyonse.

Komanso amapereka mode kupeza makina, mmene Access Nawonso achichepere angagwiritsidwe ntchito ngati SQL-kafufuzidwe jenereta aliyense gwero deta ODBC. Mbali imeneyi chimathandiza ntchito kulankhula ndi Access Nawonso achichepere mu mtundu uliwonse.

SQL yophunzitsa

Chifukwa mafunso SQL alibe maonekedwe procedural onse chinenero mapulogalamu monga zingwe zopota, nthambi, etc., opanga DBMS kukhala Baibulo awo SQL ndi zina zozama. Woyamba ndi kuthandiza ndondomeko kusungidwa ndi ntchito muyezo zinenero procedural.

M'zilembo ambiri chinenero:

• Oracle Nawonso achichepere - PL / SQL
• Interbase, Firebird - PSQL
• Microsoft SQL Server - transact-SQL
• PostgreSQL - PL / pgSQL.

SQL Internet

MySQL Nawonso achichepere adzamasulidwa pansi ufulu chilolezo License GNU General Public. Pali chilolezo malonda ndi luso kukhala zigawo mwambo. Monga mbali ya gawo yotchuka kwambiri ya maseva kumanga Internet monga XAMPP, WAMP ndi nyali ndi otchuka kwambiri Nawonso achichepere ntchito chitukuko Intaneti.

Iwo anayamba kupanga ndi Sun Microsystems ndipo panopa imayendetsedwa ndi Oracle. Amathandiza Nawonso achichepere kukula kwa terabytes 64, SQL malembedwe: 2003, kugawikana zinasokoneza makompyuta ndi ntchito mtambo.