Amfani da Kayan Kayan Kayan Kasa don Daidai Daidai
Misali na daidaituwa na SQL yana ba ka damar bincika samfurori cikin bayanai, idan ba ka san ainihin kalma ko magana kake nema ba. Irin wannan tambaya na SQL yana amfani da haruffan haruffan don dacewa da juna, maimakon ƙayyadewa daidai. Alal misali, zaka iya amfani da kalmar "C%" don dace da wani kirtani wanda ya fara da babban birnin kasar C.
Yin amfani da mai amfani kamar
Don yin amfani da wata kalma a cikin wani tambaya na SQL, yi amfani da kamfani mai kula da ita a cikin wani wuri NA, sa'annan ya ƙulla alamar ta cikin alamomi ɗaya.
Amfani da% Na'urar Don Yi Ra'ayin Bincike
Don bincika kowane ma'aikaci a cikin bayananku tare da sunan da aka fara tare da wasika C, yi amfani da bayanan Transact-SQL ta gaba:
SANTA * DAGA ma'aikatan YIN last_name LIKE 'C%'Alamar ƙetare Amfani da BABA BABI
Yi amfani da ma'anar BABI don zaɓin rubutun da basu dace da alamar ba. Alal misali, wannan tambayar ya dawo duk bayanan da sunansa na ƙarshe bai fara da C:
SANTA * DAGA ma'aikatan YAKE last_name BAYA kamar 'C%'Daidaita wata alama a kowane wuri Amfani da% Sauran Sauran Sau Biyu
Yi amfani da lokuta guda biyu na % haɗin don dacewa da juna a kowane wuri. Wannan misali ya dawo duk bayanan da ke dauke da C a ko'ina a cikin sunan karshe:
SANTA * DAGA ma'aikatan YIN last_name LIKE '% C%'Gano Matakan Samfuri a Matsayi Na Musamman
Yi amfani da maƙallan don dawo da bayanai a wani wuri. Wannan misali ya dace ne kawai idan C ya auku a matsayi na uku na shafi na karshe:
SANTA * DAGA ma'aikatan YIN last_name LIKE '_ _C%'An goge bayanan Magana a cikin Transact SQL
Akwai maganganu masu yawa da aka goyan bayan Transact SQL:
- Halin % haɗin zera ko fiye haruffa na kowane nau'i, kuma za'a iya amfani dasu don tantance maciji kafin kafin bayanan kuma. Idan kun saba da tsarin DOS daidai, yana da daidai da * cajin a wannan haɗin.
- Cikin lambar zane yana daidai da nau'i ɗaya na kowane irin. Daidai ne da ? Kira a DOS matsala daidai.
- Saka jerin jerin haruffan ta hanyar rufe su a cikin madatsai. Alal misali, eiou [jigon] ya dace da kowace wasula.
- Saka adadin haruffan ta hanyar ƙaddamar da kewayon ƙamus. Alal misali, nau'in (m) ya dace da kowace wasika a farkon rabin haruffa.
- Yi amfani da nau'in haruffan haruffa ta hanyar haɗe da halin carat a cikin cikin shinge na bude. Alal misali, [^ eiou] ya dace da duk wani nau'in bautar baƙaƙen yayin da [m] yayi daidai da kowane hali ba a farkon rabin haruffa ba.
Haɗa Ƙananan Ƙunƙwasa don Ƙananan Ƙira
Haɗa waɗannan maƙunansu a cikin alamu masu mahimmanci don gudanar da tambayoyin da suka fi dacewa. Alal misali, zaton kuna buƙatar gina jerin sunayen ma'aikatanku waɗanda suke da sunayen da suka fara da wasika daga rabi na farko na haruffa amma ba su ƙare da wasali ba. Kuna iya amfani da wannan tambaya:
SANTA * DAGA ma'aikata AKA last_name LIKE '[am]% [^ aeiou]'Hakazalika, za ku iya gina jerin sunayen ma'aikata tare da sunaye na karshe wanda ya ƙunshi nauyin haruffan hudu ta hanyar amfani da misalin huɗan hanyar :
SANTA * DAGA ma'aikatan YIN last_name LIKE '____'Kamar yadda zaku iya fadawa, yin amfani da sababbin ka'idoji na SQL yana ba masu amfani da labarun damar damar wucewa da tambayoyi masu sauƙi da kuma aiwatar da ayyukan bincike na ci gaba.