Ib tug ntau-mus-muaj coob: Ib qho piv txwv nyob rau hauv Access, nyob rau hauv SQL neeg rau. Yuav ua li cas yuav ua rau ib tug ntau-mus-muaj coob?

Tag nrho cov DBMS (database system tswj) , muaj ob peb hom kev sib raug zoo ntawm cov ntxhuav. Cov lawv ib tug-rau-ib tug, ib tug-rau-ntau, muaj coob-rau-ib (ib txhia yog inclined rau qhia ob hom mus rau hauv ib qho) thiab ntau-mus-muaj coob. Ib qho piv txwv ntawm lub yav tas, thiab piav qhia ntawm nws daim ntawv thov nyob rau hauv txawv databases, xws li Access los yog SQL, yuav tsum tau tham nyob rau hauv no tsab xov xwm.

txhais

Muaj ntau-mus-muaj coob kev sib raug zoo yog txhais raws li ib tug match rau ib yam ntawm cov ntawv luam ntawm ib qho ntawm cov essences ntawm tag nrho cov lwm yam piv txwv. Nyob rau hauv lwm yam lus, txhua teb ntawm thawj (thib ob) cov lus txuam nrog tag nrho cov teb ntawm lub thib ob (ua ntej).

Qhov no tswvyim kom meej meej qhia cov essence ntawm no kev sib raug zoo.

Thaum ib tug ntau-mus-muaj coob kev sib raug zoo muaj peev xwm yuav siv tau?

Ib qho piv txwv ntawm ib tug ntau-mus-muaj coob - ib tug me nyuam kawm ntawv pab pawg neeg thiab ib pab pawg neeg ntawm cov xib fwb. Txhua tus menyuam kawm paub ib zaug nyob rau hauv ib tug ob peb professors, uas, nyob rau hauv lem, muab lectures ob peb cov tub ntxhais kawm. Nyob hauv daim duab qhia tau hais tias qhov txawv ntawm ib tug ib tug-rau-ntau thiab ntau-mus-muaj coob.

Muaj ntau-mus-muaj coob kev sib raug zoo yog feem ntau tsim nyog nyob rau hauv qhov kev npaj ntawm loj-scale databases, me me ua piv txwv piv txwv feem ntau tsuas yog siv rau txoj kev kawm, nyob rau hauv kev muaj tiag, nyob rau hauv kev xyaum nws hloov tawm hais tias qhov ntau cov chaw nyob rau hauv lub database thiab ntau kev sib raug zoo nruab nrab ntawm lawv - lub ntau lub yuav ua rau muaj heev recourse mus rau ntau-mus-muaj coob.

Yuav ua li cas yuav ua rau ib tug ntau-mus-muaj coob?

Piv txwv ntawm kev sib raug zoo nyob rau hauv lo lus nug tseem yuav muab ntxiv nyob rau hauv lub chav kawm ntawm lub tsab xov xwm, tab sis nws yog ib qho tseem ceeb tsis tsuas mus rau to taub dab tsi nws yog, tab sis kuj yuav ua li cas los mus siv nws. Paub meej ntawm txoj kev no ncaj qha nyob rau hauv lub database xaiv rau txoj hauj lwm, thaum lub hauv paus ntsiab lus tseem tib yam rau tag nrho cov.

microsoft Access

Chaw ua hauj lwm software los ntawm "Microsoft" yog lub npe hu nyob rau hauv lub software ua lag luam rau heev ib tug ntev lub sij hawm. Nws los nrog ib tug ntawv nyeem editor Worfd, Excel tabular processor thiab lwm yam teej tug mus rau txoj kab ntawm "lub chaw ua hauj lwm". Koj muaj peev xwm Nkag (nyeem raws li "acces", lub literal translation - "nkag") kom yuav thiab cais los ntawm nws "lug txhawb cov miv". Nws yog pom zoo kom yuav, ntawm chav kawm, muaj ntawv tso cai software, tiam sis nws yog tsis muaj daim card ntau npaum li cas pirated repack yuav pom nyob rau hauv lub loj heev web, nyob rau hauv daim ntawv ntawm cov kev cov ntaub ntawv, los yog torrents ob txhais tes. "Microsoft acces" yog muaj txawm nyob rau hauv ib tug portable rooj sib txoos. Nws tsis yuav tsum tau installation thiab muaj kev tshwj xeeb kev txawj ntse mus ua hauj lwm nrog ib tug PC, nws yog zoo dua rau cov kev xaiv yog hais tias tus software yuav tsis tsum siv ntev-ntev thiab feem ntau.

Los ntawm cov ntsiab lus teb nws yog ib qhov tseeb hais tias "Microsoft acces" - ib tug database system tswj. Thiab ib qho ntawm feem nrov. Nws yog paub, uas txhais tau tias nws yog raws li nyob rau hauv cov zajlus kom cov ntaub ntawv qauv, uas yog nyob rau hauv lub chav kawm ntawm nws ua hauj lwm yog hais txog mus rau lub txheej ziag thiab thawj txiav txim logic. Muaj ntau-mus-muaj coob kev sib raug zoo nyob rau hauv Access (piv txwv yuav raug muab nyob rau hauv tus piav) yog pom tau hais heev, heev yooj yim. Xav txog nws.

Muaj ob ntxhuav ..

Nyob rau hauv thiaj li tsis mus txua ib yam dab tsi tshiab, coj lub twb hais rau piav qhia txog lub ntau-mus-muaj coob piv txwv txog cov menyuam kawm ntawv. Koj yuav tsum tsim ib lub rooj "Cov menyuam kawm ntawv" thiab cov lus "Cov xib fwb." Ob tus thawj thiab thib ob ntawm cov no yog cov thawj lub lag luam. kuj yuav tsum tau lwm lub rooj, uas teb rau combining piv txwv ntawm ob tug cov chaw - cov yuam sij ntawm tus thawj thiab thib ob ntxhuav.

Yog hais tias peb xav txog ib tug txawv piv txwv li: cia hais tias, lub players thiab pab neeg no (muab lub fact tias nyob rau hauv tsawg kawg ib tug ntawm cov players ua si rau txawv pab pawg, thiab txhua pab neeg yog muaj li ntawm kaum ib players), yog tsim tau ib tug kev twb kev txuas yuav tsis hloov. Lawv yuav tsum tau peb cov ntxhuav. Ntawm no, "Football" thiab "Team" raws li lub ntsiab thiab ib tug nrab.

cov ntaub ntawv tswvyim

Kev sib raug zoo ntawm cov ntxhuav nyob rau hauv cov database "Microsoft acces" siv siv lub tab "Cov ntaub ntawv Scheme". Cov zaub vaj huam sib luag yog ntxiv rau tag nrho cov chaw (nyob rau hauv cov ntaub ntawv no, tag nrho peb lub rooj). Tsim ib tug ntau-mus-muaj coob tus yuav tau siv cov ob kev sib raug zoo, ib tug-rau-ntau kev sib raug zoo ntawm tus thawj xib fwb ( "cov menyuam kawm ntawv" thiab "Cov xib fwb") thiab cov staging rooj. Ua li no, koj yuav tsum interconnect lub duas paub thawj lub lag luam.

Qhov kev qhia saum toj no qhia tau hais tias yuav ua li cas lub tab "cov ntaub ntawv Circuit Court" (Relathionships). Tus nab npawb ntawm ntxiv mus rau lub rooj board indefinitely. Qhov chaw yog tag nrho adjustable los ntawm tus neeg siv.

SQL

Database tsim rau SQL - nyuaj ua hauj lwm tshaj rau "acces". Yog hais tias maykrosoftovskih khoom yog siab nruj heev heev rau lub chaw ua hauj lwm ib puag ncig, muaj ib tug loj loj thiab, muaj ib tso tawm thiab hloov tag nrho cov extensible functionality, tab sis nyob rau tib lub sij hawm yooj yim rau cov yooj yim neeg interface, SQL - nws yog ib tug nyias muaj nyias ib uas tsis yog-kev programming lus, uas nyob rau txawv platforms koj yuav ua hauj lwm nrog databases. Qhov zoo-paub software rau qhov hauj lwm no: Oracle MySQL thiab DB2 (ib tug nrov, tab sis tsis yog tus tsuas yog ib qho ntawm nws hom). Txawm tias muaj tseeb hais tias txhua tus ntawm lawv muaj nws cov subtleties thiab nuances, lub SQL lus yog lawv "united". Los ntawm kev kawm ua hauj lwm muaj tsawg kawg yog ib tug ntawm lawv, mus nrog lwm leej lwm tus yuav muaj ntau yam yooj yim dua.

Tsim, sau thiab ncaj kev ua rau cov uas twb muaj lawm database nyob rau hauv SQL neeg rau yuav tsum tau los ntawm ib tug tshwj xeeb code los yog scripts. Txawm li cas los, cov neeg uas twb ua rau nws rau hauv seem "ntau-mus-muaj coob", ib qho piv txwv ntawm cov uas nyob rau hauv no programming lus yog muab hauv qab no, yuav tsum paub tsawg kawg yog qhov yooj yim commands thiab tej ntsiab cai ntawm cov SQL lus.

Lub hauv paus ntsiab lus ntawm txoj kev ib tug ntau-mus-muaj coob

Ntev accession yuav txaj muag ib co thiab "unleash pos huab", tab sis nyob rau hauv qhov tseeb lub hauv paus ntsiab lus ntawm qhov kev siv ntawm kev sib txuas lus tseem zoo li qub. Yuav kom ntaus ib tug ntau-mus-muaj coob kev sib raug zoo tau raug siv nyob rau hauv kev xyaum, tsis tsuas nyob rau hauv lub "acces", tab sis kuj cov SQL, yuav tsum chiv tsim tau ob lub hauv paus rooj thiab ib tug - intermediate. Ib yam li ntawd, nws yog ib lub tseem ceeb: qhov yooj yim xwm yog cov ntsiab teb, txhua tus uas yog sau nyob rau hauv lub linking lub rooj. Uas txhais tau hais tias cov SQL-ntau-mus-muaj coob kev sib raug zoo yog tsis fundamentally sib txawv ntawm cov "acces".

Yuav ua raws li kev sib txuas lus

Yuav kom siv ib tug ntau-mus-muaj coob nyob rau hauv ib tug SQL tsab ntawv siv lwm lub lag luam (TXAWV TEB CHAWS TSEEM) zoo ib yam li cov thawj tseem ceeb nyob rau hauv lub ntsiab lus. Lawv kaw ua ke nrog tag nrho cov teb thaum tsim thiab / los yog editing.

Lub luag hauj lwm ntawm ib tug ntau-mus-muaj coob

Nyob rau hauv dav dav, lub kev sib raug zoo ntawm cov chaw nyob rau hauv lub database siv rau lub sam xeeb ntawm cov ntaub ntawv khaws tseg nyob rau hauv lawv. Tsuas yog ib tug zoo-tsim database nrog txhua tus tsim nyog kev sib txuas kom muaj kev ruaj ntseg cia, cov neeg siv kev kawm txawj thiab yog ib tug qauv uas yog resistant mus rau sab nraud influences thiab hloov. Feem ntau, yog hais tias tus database muaj cov ntaub ntawv nyob rau tag nrho lub koom haum, tuam txhab los yog ruaj, nws muaj ib tug txheej ntawm cov chaw uas muaj ntau zaus.

Qhov no txhais tau tias nyob rau hauv qhov kev npaj ntawm cov schemes ( "acces") los yog sau ntawv scripts (nyob rau hauv lub "Oracle" los yog "DiBiTu") yuav tsum tam sim no tsawg kawg yog ib ntau-mus-muaj coob. Piv txwv li SQL neeg rau, yog feem ntau siv rau txoj kev kawm cov hoob kawm "Database Organization" - DB King.

Base ntawm King cov ntaub ntawv

Txoj kev kawm database yog cov ntaub ntawv hais txog huab tais corporation. Ntawm cov ntxhuav:

• neeg ua hauj lwm ntawm lub tuam txhab - muaj cov neeg ua hauj lwm ID, lub xeem lub npe, thawj lub npe thiab nruab nrab (kom pom tseeb rau txawv teb chaws lub npe), kuj code rau cov thawj coj thiab cov neeg ua hauj lwm nyob rau hauv lub txoj hauj lwm, hnub mus kawm rau lub npe tau txais lawv cov nyiaj hli thiab nyiaj pab, department code;
• departments ntawm corporations - ntawm cov teb ntawm lub rooj muaj lub code thiab lub npe ntawm lub tuam tsev, raws li zoo raws li cov kev cai ntawm nws qhov chaw nyob;
• kev tso kawm departments, uas yuav nkag mus kawm ntaub ntawv nyob rau hauv lub code kawm thiab lub npe ntawm lub nroog;
• txoj hauj lwm nyob rau hauv lub tuam txhab - ib tug me me rooj nrog ob tug teb rooj vag code thiab nws cov nom lub npe;
• npe-buyers - teb: cov code thiab lub npe ntawm tus buyer, chaw nyob, lub zos, lub xeev, zip code thiab area code, xov tooj, kev pab saib xyuas ntawm tus neeg muas zaub code, cov credit rau lub buyer thiab comments (comments thiab sau ntawv);
• muag ntawv cog lus, uas muaj lub code thiab lub hnub ntawm daim ntawv cog lus, lub buyer code, tus me nyuam hnub thiab tag nrho cov nqi ntawm daim ntawv cog lus;
• Tubtxib Tes Haujlwm ntawm kev muag khoom - ua los ntawm cov code thiab lub code ntawm daim ntawv cog lus, uas muaj xws li cov kev ua, cov khoom code, nws cov nqi, kom muaj nuj nqis muas thiab tag nrho cov purchase them nqi;
• Cov khoom - cov code npe ntawm cov khoom;
• nqi - cov khoom code, tshaj tawm rau nws tus nqi, tus nqi qis tshaj tau nqi, hnub lag luam thiab lub hnub ntawm lub tso tseg nqi.

Lub rooj me me muaj nyob rau hauv uas tsis muaj ntau tshaj li ob los yog peb teb txuam nrog mus txog rau ib lub rooj ntawm ib tug ib tug-rau-ib tug los yog ib tug-rau-ntau.

Nplai tib lub rooj, xws li "neeg ua hauj lwm ntawm lub tuam txhab", "lub tuam txhab-tau txais kev pab", "muag khoom agreements" thiab "ua ntawm kev muag khoom" yog txuam nrog rau ob peb qhov chaw, muaj ib co - nrog rau cov kev pab los ntawm "intermediaries" ntau-mus-muaj coob sib raug zoo. Rooj "buyers ntawm lub tuam txhab" yog nws tus kheej ib tug intermediary, xws li, vim hais tias nws muaj ntau lub teb, los ntawm lwm yam ntxhuav thiab ib tug txawv teb chaws tseem ceeb. Nyob rau hauv tas li ntawd, lub teev thiab cov kev sib raug zoo database "King Corporation" yog hais tias tag nrho cov kev sib raug zoo yog inextricably correlated nrog txhua lwm yam thiab kev cuam tshuam rau ib leeg. Cov kev puas tsuaj ntawm tsawg kawg yog ib tug ntawm lawv yuav ua rau kom cov kev puas tsuaj ntawm cov kev ntseeg ntawm tag nrho cov database.

ib qho tseem ceeb nuances

Thaum siv ib tug ntau-mus-muaj coob, hais txog ntawm uas database system tswj yog siv, nws yog ib qho tseem ceeb los mus txiav txim qhov tseeb lub lag luam uas yuav tau kos mus txog tus cwj pwm. Incorrectly DVR qhov kev twb kev txuas tsis txaus siab nws cov ntsiab lub hom phiaj - namely, los xyuas kom meej lub meej mom ntawm lub rooj, thiab raws li ib tug tshwm sim, es tsis txhob tsim kev nplij siab, tus neeg siv yuav tau txais, rau lwm cov tes, tus txaav thiab ntxiv teeb meem, tshwj xeeb yog tshwm thaum lub sij hawm sau ntawm editing ntxhuav thiab lawv cov ntaub ntawv.