U etsa lipotso joang ho MongoDB?

Mokhoa oa ho etsa lipotso ho MongoDB

MongoDB ke polokelo ea lintlha mohloli o bulehileng o sebelisang sebopeho sa litokomane ho boloka le ho hlophisa tlhahisoleseling. Ke khetho e tsebahalang haholo lefats'eng la nts'etsopele ea webo ka lebaka la scalability ea eona le ho feto-fetoha ha maemo. Ka lipotso, hoa khoneha ho batla lintlha tse itseng ka har'a pokello ea litokomane. Sehloohong sena, re tla hlahloba mekhoa e fapaneng ea ho botsa MongoDB le mokhoa oa ho fumana molemo ka ho fetisisa sesebelisoa sena se matla sa ho batla.

Mefuta ea lipotso ho MongoDB

MongoDB e fana ka mekhoa e fapaneng ea ho botsa lipotso tsa eona li-database. Potso ea mantlha ke ho batla litokomane tse tsamaellanang le sehlopha sa ⁤ maemo a itseng. Bakeng sa sena, mokhoa ona o sebelisoa fumana () mmoho le ntho ea potso e nang le lintlha tsa ho batla. Ts'ebetso ena e khutlisa cursor, e ka phetoang ho fumana liphetho tsa potso.

Lipatlisiso tse nang le basebelisi ba utloahalang

Ntle le potso ea mantlha, MongoDB e fana ka ⁢ basebelisi ba nang le kelello ba lumellang lipatlisiso tse tsoetseng pele. Basebelisi ba logic ba rata $le, $kapa y $ha ho joalo Li ka kopanngoa ho theha lipotso tse rarahaneng tse kenyelletsang maemo a mangata. Mohlala, re ka batla litokomane tse fihlelang litekanyetso tse peli re sebelisa opareitara $le. Ho etsa sena, ntho ⁢e nang le boemo bo bong le bo bong ka har'a opareita⁤ e tlameha ho hlalosoa potsong.

Lipuisano tse nang le projeke

MongoDB e u lumella ho etsa lipotso ka projeke ea ho fokotsa masimo a khutlisetsoang liphethong. Sena se finyelloa ka ho sebelisa mokhoa⁤ morero() kapa ka ho hlakisa hore na ke likarolo life tse lokelang ho kenyelletsoa kapa ho qheleloa ka thoko⁤ potsong. Ts'ebetso ena e bohlokoa ha ho hlokahala feela karoloana ea likarolo tsa litokomane, ho fokotsa boholo ba karabo le ho potlakisa ts'ebetso ea lipotso.

Hlopha le ho fokotsa liphetho

Maemong a mangata, hoa hlokahala taelo kapa moeli liphetho tsa potso ho MongoDB. Ho etsa sena, mekhoa e ka sebelisoa. hlopha () y moeli (). ⁢Mokhoa⁤ hlopha () e u lumella ho hlophisa liphetho ho latela sebaka se le seng kapa ho feta, ha u ntse u moeli () e fokotsa palo ea litokomane tse khutlisitsoeng. Mesebetsi ena e thusa ho hlophisa le ho laola palo ea lintlha tse fumanoeng, ho fana ka liphetho tse nepahetseng le tse sebetsang hantle.

Ho tseba ho etsa lipotso ho MongoDB ho bohlokoa ho nka monyetla ka botlalo ka monyetla⁤ oa database ena. Ka likhetho tse fapaneng tsa lipotso, o ka batla lintlha tse ikhethileng, oa theha lipotso tse rarahaneng, 'me u fokotsa liphetho ho eketsa ts'ebetso. Ka ho itloaetsa le kutloisiso ea mekhoa le li-operators tse fapaneng, u tla khona ho botsa lipotso ka nepo le ho fumana lintlha tse lakatsehang kapele le ka nepo.

- Kenyelletso ea lipotso ho MongoDB

MongoDB ke database ea NoSQL e bonolo haholo ebile e tenyetseha e u lumellang ho boloka tlhaiso-leseling e ngata. E 'ngoe ea likarolo tse matla ka ho fetisisa tsa MongoDB ke bokhoni ba eona ba ho etsa lipotso tse tsoetseng pele ka katleho. Ka lipotso tsena, bahlahisi ba ka fumana lintlha tse ikhethileng ho tsoa ho database ho latela litlhoko tsa bona.

Lipotso ho MongoDB li etsoa ho sebelisoa Structured Query Language (SQL) 'me li bitsoa "lipotso⁢ ka syntax ea lipotso⁢." Lipotso tsena li hlalosoa ka mokhoa oa litokomane tsa JSON 'me li romelloa ho database. Lintlha tsa MongoDB bakeng sa ho phethahatsoa ha eona. Lipotso li ka kenyelletsa maemo, likhakanyo, mefuta, le lithibelo ho sefa le ho laola lintlha ka nepo.

Karolo ea bohlokoa ea lipotso ho MongoDB⁢ ke bokhoni ba ho sebelisa li-index ho ntlafatsa ts'ebetso ea lipotso. Li-index ho MongoDB ke libopeho tsa data tse bolokang karoloana ea pokello ea lintlha ka mokhoa o lokiselitsoeng ho botsa kapele. Li-index li ka etsoa tšimong e le 'ngoe kapa ho feta pokellong le ho potlakisa phihlello ea data ka ho fokotsa palo ea litokomane tse lokelang ho hlahlojoa nakong ea potso. Ho sebelisa ts'ebetso ena ka botlalo, ho bohlokoa ho rala le ho kenya tšebetsong li-index tse nepahetseng bakeng sa boemo bo bong le bo bong ba tšebeliso.

- Syntax ea mantlha bakeng sa lipotso

Ha re se re e-na le database ea rona le likoleke tsa rona tse entsoeng MongoDB, mohato o latelang ke ho ithuta ho etsa lipotso. MongoDB e sebelisa puo ea eona ea ho botsa e bitsoang Query Language (QL). Ka QL re ka etsa lipotso tse rarahaneng ka tsela e bonolo le e sebetsang hantle.

Syntax ea mantlha ea ho botsa MongoDB ke ho sebelisa mokhoa db.collection.find().⁢ Mokhoa ona o re lumella ho batla litokomane ka har'a pokello e fihlelang litekanyetso tse itseng. Ho hlakisa mekhoa ea ho batla, re sebelisa ntho ea JSON e le khang ea mokhoa oa ho fumana.

Ha re se re entse potso ea rona, re ka sebelisa basebelisi ba fapaneng ho ntlafatsa sephetho. MongoDB ⁤e fana ka mefuta e mengata e fapaneng ea basebelisi, e re lumellang ho etsa lipotso tse hlakileng le tse hlakileng haholoanyane. Tse ling tsa li-operator tse tsebahalang haholo ke:

• $eq: ho botsa haeba boleng ba lebala bo lekana ⁤ le boleng bo bong bo boletsoeng.
• $ne: ho hlahloba hore na boleng ba tšimo ha bo lekane le boleng bo bong bo boletsoeng.
• $gt: ho botsisisa hore na boleng ba lebala bo⁤ bo boholo ho feta boleng bo bong bo boletsoeng.
• $lt: ho lekola hore na boleng ba lebala bo ka tlase ho boleng bo bong bo boletsoeng.

Tsena ke tsona feela mehlala e meng ea basebelisi ba fumanehang MongoDB. Ho phaella ho tsena, ho na le basebelisi ba bangata⁤ ba bangata ba re lumellang ho etsa lipotso tse rarahaneng. Ka ho kopanya basebelisi le mekhoa ea ho batla, re ka fumana liphetho tse hlakileng le tse tlhotliloeng ho tsoa ho database ea rona.

- Tšebeliso ea papiso⁤ le li-operators tse utloahalang lipotsong

Ho MongoDB, tšebeliso ea papiso le basebedisi ba utloahalang "Lipotso" li re fa monyetla oa ho etsa lipatlisiso tse tsoetseng pele le tse nepahetseng ka har'a pokello ea lintlha. Basebelisi bana ba sebelisoa ho sefa litokomane tse fihlelang maemo a itseng. Ka ho li kopanya hantle, re ka fumana liphetho tse tobileng le tse loketseng.

The bapapatsi ba bapisang ho MongoDB kenyeletsa $eq bakeng sa tekano, $ne bakeng sa ho se lekane, $gt bakeng sa kholo ho feta, $gte ho feta kapa ho lekana le, $lt ⁢ ka tlase ho le $lte ka tlase ho kapa ho lekana le. Basebelisi bana ba sebelisoa ho bapisa lipalo, likhoele tsa mongolo, le mefuta e meng ea data litokomaneng tsa rona. Mohlala, re ka batla litokomane tsohle tse nang le karolo ea "lilemo" e kholo ho feta kapa e lekanang le 18 re sebelisa opareitara $gte.

The basebetsi ba utloahalang ho MongoDB e kenyelletsa⁢ $le, $kapa y $ha ho joalo. Lisebelisoa tsena ⁢ li sebelisoa ho kopanya maemo a mangata potsong e le 'ngoe. Mokhanni $le lumella ho fumana litokomane tse ka nako e le 'ngoe kopana le maemo a' maloa, ha opareitara e $kapa Fumana litokomane tse fihlelang bonyane maemo a le mong. Ka lehlakoreng le leng, opareitara $ha ho joalo e sebelisetsoa ho hana boemo, ke hore, ho fumana litokomane tse sa finyelleheng. Ka ho sebelisa li-operators tsena tse utloahalang, re ka theha lipotso tse rarahaneng le tse bonolo ho MongoDB.

- Lipotso tse sebelisang mantsoe a tloaelehileng

MongoDB ke database ea NoSQL e lumellang ho botsa ka mokhoa o bonolo ho sebelisa lipolelo tse tloaelehileng. Litlhaloso tse tloaelehileng ke mekhoa ea mongolo e sebelisoang ho batla litlhaku tse ngata ka har'a sebaka se itseng pokellong ea litokomane. Lipotso tsena li ka u thusa haholo ha u batla tlhahisoleseling ho latela mokhoa o itseng, joalo ka nomoro ea mohala, aterese ea lengolo-tsoibila kapa zip code. Ho MongoDB, mantsoe a tloahelehileng a sebelisoa mmoho le `$regex` opareitara,⁢ e u lumellang ho batla lintho tse tšoanang ka har'a lebala.

Mohlala, ha re re⁢ re na le pokello ea litokomane tse nang le lintlha tsa bareki. Haeba re batla ho fumana bareki bohle bao mabitso a bona a qalang ka tlhaku "J", re ka sebelisa polelo e tloaelehileng `/^J/`. Ka sena, potso e tla batla litokomane tsohle tseo tšimo ea "lebitso" la tsona e qalang ka tlhaku "J". Hape hoa khoneha ho batla bareki bohle bao mabitso a bona a nang le tatellano ea litlhaku "mora" boemong bofe kapa bofe, ho sebelisoa polelo e tloaelehileng `/son/`.

Ntle le ts'ebetso ea mantlha ea ho batla, MongoDB e boetse e u lumella ho kopanya mantsoe a tloaelehileng le basebelisi ba bang ho etsa lipotso tse thata. Ka mohlala, re ka etsa potso e tla fumana bareki bohle bao mabitso a bona a qalang ka tlhaku "J" le bao nomoro ea bona ea mohala e nang le tatellano ea "123". Ho etsa sena, re ka sebelisa `$and` opareitara hammoho le lipoleloana tsa kamehla. Tabeng ena, potso e tla ba ntho e kang ena: `{$le: [ {lebitso: {$regex: /^J/ }}, {mohala: {$regex: /123/}}] }`.

- Ho sebelisa li-index ho ntlafatsa ts'ebetso ea lipotso

Ho na le mekhoa e fapaneng e ka sebelisoang ho ntlafatsa ts'ebetso ea lipotso ho MongoDB, e 'ngoe ea tsona ke ts'ebeliso ea li-index. Li-index ho MongoDB ke libopeho tsa data tse ntlafatsang katleho ea lipotso ka ho lumella phihlello e potlakileng ea tlhaiso-leseling e bolokiloeng polokelong. Ka ho sebelisa li-index hantle, E ka finyelloa lipotso li sebetsa hantle 'me nako ea ho arabela e fokotsehile⁤.

Ho sebelisa li-index ho MongoDB, u tlameha ho qala ka ho etsa index ea pokello eo u batlang ho e supa. MongoDB e fana ka mefuta e fapaneng ea li-index tse kang li-index tsa masimo a le mong, li-index tsa composite, le li-geospatial indexes. Mofuta oa index oo u tla o sebelisa o tla ipapisa le mofuta oa data le mofuta oa potso eo u batlang ho e etsa. Hang ha index e se e thehiloe, MongoDB e tla sebelisa index ka bo eona ho ntlafatsa ts'ebetso ea lipotso tse fihlellehang pokellong.

Ho bohlokoa ho hlokomela hore leha li-index li ntlafatsa ts'ebetso ea lipotso, li boetse li ama ts'ebetso ea ts'ebetso ea ho ngola. Sena ke hobane nako le nako ha ho etsoa opereishene ea ho ngola e amang ho ea tokomaneng indexed, MongoDB e tlameha ho ntlafatsa li-index tse tsamaellanang. Ka hona, hoa hlokahala ho fumana tekano lipakeng tsa ts'ebetso ea lipotso le ts'ebetso ea ho ngola. Maemong a mang, ho ka 'na ha hlokahala hore ho etsoe liphetoho ho leano la indexing ho finyella tshebetso e nepahetseng ea database.

- Lipotso le ts'ebetso e kopaneng ho MongoDB

MongoDB ⁤ke polokelo ea polokelo ea NoSQL ⁢e lumellang hore lipotso li etsoe hantle le ka mokhoa o bonolo. E 'ngoe ea likarolo tse matla ka ho fetisisa tsa MongoDB ke lipotso tse fanoeng, e u lumellang ho batla litokomane tse nang le lintho tse ka har'a lintho tse ling. Sena se bohlokoa haholo ha re sebetsa ka data e rarahaneng 'me re batla ho botsa lipotso tse nepahetseng.

Ho etsa potso e hlophisitsoeng ho MongoDB, re sebelisa opareitara ea matheba («.») ho fihlella likarolo tse ka hare tsa tokomane. Ka mohlala, haeba re e-na le pokello ea litokomane tsa bareki 'me tokomane ka' ngoe e na le sebaka sa "aterese", 'me eona e na le libaka tse kang "seterata," "toropo" le "naha," re ka botsa ho fumana bareki bohle ba lulang. motseng kapa naheng e itseng.

Ntle le lipotso tse fumanehang, MongoDB e boetse e fana ka ts'ebetso ea ho kopanya tse re lumellang ho etsa lipalo tse rarahaneng ho data ea rona. ⁢Ts'ebetso ena e re lumella ho etsa mesebetsi e kang ho eketsa, ho bala, ho beha karolelano, kapa ho fumana boleng ba holimo kapa bo tlase⁤ ba sebaka se itseng pokellong ea rona ea litokomane.

Ts'ebetso ea ho kopanya ho MongoDB e etsoa ka liphaephe, e leng ⁢ tatelano ea methati moo mohato ka mong o etsang ⁢phetoho litokomaneng. Re ka sebelisa mekhahlelo e fapaneng ea lipeipi, joalo ka $match ho sefa litokomane tseo re batlang ho li kenyelletsa potsong, $group ho ea ka lihlopha ho latela maemo, $project ho khetha likarolo tseo re batlang ho li bontša liphetho. , hara ba bang. Ts'ebetso ena ea ho kopanya e re fa monyetla o moholo oa ho etsa lipalo le tlhahlobo e tsoetseng pele ho data ea rona e bolokiloeng ho MongoDB.

- Litlhahiso tsa ho ntlafatsa lipotso ho MongoDB

Ho ntlafatsa lipotso ho MongoDB, ho bohlokoa ho latela likhothaletso tse itseng. Pele ho tsohle, ho kgothaletswa etsa li-index tse loketseng bakeng sa lipokello tse tla botsoa khafetsa Li-Index ho MongoDB li thusa ho potlakisa ho khutlisa data ka ho lumella enjene ea polokelo ea litaba ho batla tlhahisoleseling ka katleho. Ho etsa sena, o tlameha ho sekaseka lipotso tse tla etsoa khafetsa le ho theha li-index masimong a sebelisoang lipotsong tseo.

Tlhahiso e 'ngoe ea bohlokoa ke fokotsa masimo a khutlisitsoeng ka lipuisano. Ha o etsa potso ho MongoDB, o ka hlakisa libaka tseo u batlang ho li khutlisa. Ho bohlokoa hore⁢ ho khutlisetsoe likarolo tse hlokahalang feela ho fokotsa boholo ba ⁤ litokomane le ho ntlafatsa ts'ebetso ea lipotso. Sena Ho ka etsoa ho sebelisa projeke ho MongoDB, ho bonts'a masimo a hlokahalang ka mokhoa find().

Qetellong, khothaletso ⁢ ea bohlokoa ke ⁢ sebelisa aggregation ho fapana le lipotso tse ngata ha ho khoneha. Aggregation ho MongoDB e lumella lits'ebetso tsa lipotso tse ngata ho kopanngoa hore e be e le 'ngoe' me e fana ka tshebetso e phahameng. Sena se bohlokoa haholo ha o etsa lits'ebetso tse kang ho sefa, ho hlophisa ka lihlopha, le ho bala lipalo-palo ho data. Ka ho sebelisa aggregation, u qoba mokhoa oa ho fetisa data pakeng tsa seva le kopo, e lebisang ho tshebetso e ntlafetseng le moroalo o fokolang inthaneteng.