Ana dawo da bayanan daga Mahimun Tables tare da SQL Inner shiga

Inner ya haɗa da bayanan sake dawo da bayanan da ya bayyana a cikin bayanai biyu ko fiye

Ƙungiyar haɗin ciki an fi amfani dashi akai cikin SQL. Sun dawo ne kawai bayanan da yake samuwa a cikin ɗakunan bayanai biyu ko fiye. Yanayin haɗin yana ƙayyade abin da aka rubuta rubutun tare kuma an ƙayyade shi a cikin SABARI wannan sashe. Alal misali, idan kuna buƙatar jerin takardun direbobi / motar da abin hawa da direba suke a cikin birni ɗaya, tambayar SQL ɗin da ke biyowa ya cika wannan aikin:

SANTA sunan mai suna, sunan farko, tag DAGA direbobi, motocin WANTA direbobi.location = motoci.location

Ga sakamakon:

sunan sunan mai suna name
---------------------- ----
Baker Roland H122JM
Smythe Michael D824HA
Smythe Michael P091YF
Jacobs Ibrahim J291QR
Jacobs Ibrahim L990MT

Ka lura cewa sakamakon shine daidai abin da aka nema. Zai yiwu a kara tsaftace tambayar ta hanyar ƙayyade ƙarin ƙayyadaddun wuri a WANNAN SAN. Yi la'akari da tambaya na ainihin ya dace da direbobi zuwa motocin da basu da ikon izini (direbobi na motoci zuwa motoci da kuma mataimakin mugunta). Kuna iya amfani da wannan tambaya don magance wannan matsala:

Sake sunan mai suna, sunan farko, tag, vehicles.class DAGA direbobi, motocin MUTANE drivers.location = motocin motocin da kuma drivers.class = vehicles.class

Wannan misali ya ƙayyade maɓallin tushe ga ɗalibin sifa a cikin sashen SELECT saboda kullin ba shi da kyau-yana bayyana a duka tebur. Kodin zai ƙayyade yawan wane shafi na launi ya kamata a haɗa shi a sakamakon binciken. A wannan yanayin, ba ta da bambanci, don ginshiƙan suna da kyau kuma an haɗa su ta amfani da kayan aiki. Duk da haka, idan ginshiƙai sun ƙunshi bayanai daban-daban, wannan bambanci zai zama mahimmanci. Ga sakamakon wannan tambaya:

sunan sunan mai suna na farko
---------- ------------ ---- ------
Baker Roland H122JM Car
Smythe Michael D824HA Truck
Jacobs Ibrahim J291QR Car

Wadanda aka bace sun hada da Michael Smythe zuwa mota da Ibrahim Jacobs zuwa motoci, motocin da basu basu izini ba.

Hakanan zaka iya amfani da haɗin ciki don haɗa bayanai daga launi uku ko fiye .