Bhuku raKushandisa Inner Joins Joins muSQL kuGulu Dhiyabhorosi kubva paTables Multiple

Shandisa SQL Inner Joins kubatanidza data kubva pamatafura matatu kana kupfuura

Iwe unogona kushandisa SQL JOIN mazwi okubatanidza data kubva pamatafura matatu kana kupfuura. SQL KUTAURA inonyatsochinja, uye simba rayo rinoshanda rinogona kushandiswa kubatanidza data kubva pamatafura akawanda. Ngatitarisei zvinyorwa zveSQL zvinokubvumira kuti mubatanidze migumisiro kubva kumatafura matatu akasiyana achishandisa kubatana kwemukati.

Inner Join Example

Somuenzaniso, tora matafura ane vatyairi mune imwe tafura uye motokari dzinoenderana-siyana mune yechipiri. Kubatana kwemukati kunowanikwa apo motokari nemutyairi zviri muguta rimwe chete. Inhengo yepakati inosarudza mitsetse yose kubva kumatafura ose ane mutsanana pakati pekugara kwema column.

Izwi reSQL riri pasi apa rinobatanidza data kubva kumatokari nevatori vematafura mumamiriro ezvinhu apo mutyairi nemotokari zviri muguta rimwe chete:

SELECT lastname, firstname, tag FROM drivers, motokari PANE vatyairi.location = motokari.kuendesa

Uyu mubvunzo unobereka zvinotevera:

zita rekutanga tag -------- --------- --- Baker Roland H122JM Smythe Michael D824HA Smythe Michael P091YF Jacobs Abraham J291QR Jacobs Abraham L990MT

Iye zvino, taura muenzaniso uyu kuisa tafura yechitatu. Fungidzira iwe waida kuisa chete vanodhairi uye motokari dziripo munzvimbo dzinovhurwa muvhiki. Iwe unogona kuuya nefura yechitatu mubvunzo wako nekuwedzera izwi reJOIN sezvinotevera:

SELECT lastname, firstname, tag, open_weekends KUBVA vatyairi, motokari, nzvimbo WHERE vatyairi.location = motokari.kugadzirisa uye imotokari.location = nzvimbo.kugadzirisa uye nzvimbo.open_weekends = 'Hungu' zita rekutanga zita rekuvharika_kugadzirira -------- --------- --- ------------- Baker Roland H122JM Hongu Jacobs Abraham J291QR hongu Jacobs Abraham L990MT hongu

Ichi chinowedzera simba kune chekutanga SQL JOIN statement inokubvumira kusanganisa data nenzira yakaoma. Mukuwedzera pakubatanidza matafura ane kubatana kwemukati, unogonawo kushandisa nzira iyi yekubatanidza matafura akawanda uchishandisa kubatana kwekunze. Kunze kwekunze kunosanganisira migumisiro iripo patafura rimwe chete asi haina mutsara wakafanana mubheji rakabatanidzwa.