Harshen Sakamakon Lissafi yana bayan bayanan bayanan bayanan zamani
Siffar da ake kira Structured Query Language (SQL) ita ce harshen databases. Duk bayanan bayanan zamani, ciki har da Access, FileMaker Pro, Microsoft SQL Server da Oracle amfani da SQL a matsayin asalin ginin su. A gaskiya ma, sau da yawa shine hanyar da za ka iya hulɗa tare da database kanta. Dukkan mai amfani da aka tsara wanda ke ba da shigarwar bayanai da kuma aikin sarrafawa ba kome bane ne kawai masu fassarar fassarorin SQL. Suna daukar ayyukan da kake yi a cikin hoto kuma suna mayar da su zuwa ga dokokin SQL da suka fahimta.
SQL yana kama da Turanci
A wannan lokaci, zaku iya tunanin cewa ba mai tsarawa ba ne kuma koyon harshe na shirye-shiryen ba lallai ba ne a kan hanyarku ba. Abin farin, a ainihinsa, SQL wani harshen ne mai sauki. Yana da ƙayyadadden adadin umarni, kuma waɗannan umarni suna da karfin gaske kuma suna da kusan tsari kamar kalmomin Ingilishi.
Gabatar da Databases
Don fahimtar SQL, yana da mahimmanci a fahimtar yadda bayanai suke aiki. Idan kuna jin dadi tare da sharuddan kamar "tebur," "dangantaka," da "tambaya," suna jin kyauta don yadawa a gaba! Idan ba haka ba, kuna iya karanta labarin Database Fundamentals kafin motsi.
Bari mu dubi misali. Yi la'akari da cewa kuna da kwarewa mai sauƙi wanda aka tsara don kiyaye kaya don saurin kantin kayan aiki. Ɗaya daga cikin Tables a cikin bayanan ku na iya ƙunsar farashin abubuwan a kan ɗakunanku waɗanda aka ƙididdige su ta hanyar lambobi masu mahimmanci da suka gano kowane abu. Kila za ku ba wannan tebur mai sauki kamar "Prices."
Wata ila kana so ka cire abubuwa daga kantinka wanda aka saka farashin fiye da $ 25, za ka "nema" bayanai don jerin waɗannan abubuwa duka. Wannan shine inda SQL ya shiga.
Bincikenku Na Farko na farko
Kafin mu shiga bayanin da aka buƙata na SQL don buƙatar wannan bayani, bari muyi kokarin yin tambayoyi a cikin harshen Turanci. Muna so mu "zaɓar duk lambobi daga farashin farashi inda farashin ya wuce $ 25." Wannan kyauta ne mai sauki idan aka bayyana a cikin harshen Turanci, kuma yana da kusan kamar sauki a cikin SQL. Ga bayanin sanarwa na daidai:
Sanya StockNumber
FROM Prices
YADDA BAYA> 5
Yana da sauki kamar wancan! Idan kun karanta sanarwa da ke sama da ƙarfi, za ku ga cewa yana da kama da ƙwararren Ingilishi da muka gabatar a cikin sakin layi na ƙarshe.
Fassara Bayanan SQL
Yanzu bari mu gwada wani misali. A wannan lokaci, duk da haka, zamu yi baya. Na farko, Zan samar muku da sanarwa na SQL kuma bari mu ga idan za ku iya bayyana shi a cikin harshen Turanci:
Fara farashin
FROM Prices
YADDA StockNumber = 3006
Don haka, me kuke tunani wannan bayani yake? Gaskiya ne, yana dawo da farashin daga ma'afin bayanai don abu 3006.
Akwai darasi mai sauƙi da ya kamata ka dauke daga tattaunawa a wannan batu: SQL kamar Ingilishi ne. Kada ku damu da yadda kuke gina maganganun SQL; za mu sami wannan a sauran jerinmu. Kamar gane cewa SQL ba kamar yadda tsoratarwa kamar yadda na iya fara bayyana.
Matsayin Bayanan SQL
SQL yana samar da fadi da kewayon maganganu, wanda SELECT ɗaya ne kawai. Ga wasu misalai na sauran maganganu na kowa na kowa:
- SQL Sanya da SQL KASHE: Abun da ke sanyawa ko kuma share wani rikodin daga tebur
- SQL UPDATE: Sauya bayanan a cikin tebur
- SQL CREATE da SQL DROP: Ya ƙirƙira ko ya share teburin
Bugu da ƙari ga waɗannan maganganun SQL, za ka iya amfani da kalmomin SQL, daga cikinsu akwai inda aka yi amfani da su a cikin misalai na baya. Wadannan sashe suna tsaftace irin bayanai don aiki. Baya ga ma'anar WHERE, akwai wasu sharuddan da aka saba amfani dashi:
- AND ko OR: Haɗa yanayi mai yawa don tsaftace sanarwa na SQL
- YADDA: Yana kwatanta darajar da ta dace da dabi'un da aka yi amfani da su
- KARANTA DA: Sakamakon bayanai a hawan sama ko saukowa
Idan kuna sha'awar karin bincike SQL, SQL Fundamentals ne mai yawa-part tutorial cewa bincika da aka gyara da al'amurran da SQL a cikin ƙarin daki-daki ,.