Ekuphathweni kwesizindalwazi, umsebenzi ojwayelekile ovame ukubhekana nawo onjiniyela ukuthola nokukhomba amathebula athile kusizindalwazi ngamagama abo. Lo msebenzi ubalulekile ezimeni ezinjengokulungisa iphutha, ukuhlanzwa kwedatha, ukwenza ngcono ngisho nasekubhaleni i-schema sedathabhesi. I-SQL, ulimi olujwayelekile lokuphatha nokuphatha imininingwane egciniwe yobudlelwano, inikeza izixazululo zepragmatic kuleyo misebenzi.
Ukuthola Amathebula Anegama Eliqondile ku-SQL
I-SQL inikeza ububanzi obuhlukahlukene bemiyalo nemisebenzi engasetshenziswa ukubuyisa imethadatha emayelana nesizindalwazi. Le methadatha ihlanganisa ulwazi olumayelana namathebula, njengegama lethebula, i-schema sethebula, idatha esethebula njll. Ku-SQL, lokhu kuphathwa ngesitatimende esithi KHETHA kanye nethebula elithi INFORMATION_SCHEMA.TABLES eliyingxenye yokucaciswa okujwayelekile kwe-SQL.
SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = 'your_table_name';
Incazelo yesinyathelo ngesinyathelo yeKhodi
Ake sihlukanise lo myalo we-SQL ukuze siqonde ukuthi yenza kanjani isenzo sokuthola ithebula kusizindalwazi.
KHETHA * igama elingukhiye le-SQL elimele 'khetha konke'. Lokhu kuhloselwe ukukhombisa wonke amakholomu kuthebula esikhetha kulo.
KUSUKA KU-INFORMATION_SCHEMA.TABLES ingxenye lapho sikhomba ithebula esikhetha kulo idatha. INFORMATION_SCHEMA.TABLES ithebula elikhethekile eliphethe imethadatha emayelana namathebula akhona kusizindalwazi.
LAPHO TABLE_NAME = 'igama_letafula_lakho' umbandela wokukhetha. Sifuna ulwazi mayelana nethebula legama elithile.
Ngakho-ke, umyalo umba imethadatha yesizindalwazi sakho, uzingela amatafula anegama elishiwo futhi ubuyisela ulwazi ngakho.
Ithebula elithi INFORMATION_SCHEMA.TABLES
I-INFORMATION_SCHEMA 'i-schema yesistimu' esibukeka kubo bonke abasebenzisi. Kuyisethi evamile yokubuka okuhlanganisa TABLES, COLUMNS, KEY_COLUMN_USAGE, nokunye. Lokhu kubuka kunikeza ukufinyelela imethadatha emayelana nesizindalwazi, okuhlanganisa ulwazi olumayelana namathebula ayo.
Ukusebenza ngeDatabase Libraries
Ngokungeziwe ezindleleni ezihlinzekwe yi-SQL, izilimi eziningi zokuhlela zinemitapo yolwazi evumela ukusebenzisana nesizindalwazi. Isibonelo semitapo yolwazi enjalo e-Python yi-psycopg2, okuyi-adaptha ye-PostgreSQL. Ngokufanayo, ku-MySQL, pymysql, kanye ne-Oracle, i-cx_Oracle isetshenziswa. Ngokusebenzisa la mamitapo, uzokwazi ukusebenzisana nezizindalwazi ze-SQL, wenze imiyalo ye-SQL futhi ulande imiphumela kukhodi yakho.
Sengiphetha, singasho ukuthi i-SQL inikeza indlela enamandla kakhulu nenembile yokusebenza nemethadatha yesizindalwazi ngesethi yayo evamile yokubuka.
Khumbula, kubalulekile ngaso sonke isikhathi ukuqonda ulwazi osebenza nalo kusizindalwazi sakho, futhi imisebenzi yosesho ingasiza kakhulu ukuthola, ukuzulazula, nokuphatha amathebula akho.
