Oracle SQL INNER Join based on non-matching values

问题

ColA(Table1)     ColB(Table2)
AB3               AB_MNO_3
AB3               AB_PQR_3
AB4               AB_MNO_4
AB4               AB_PQR_4

I want to do Inner Join based on columns in two table with some of the non-equal values shown above. So, Table1 can have AB3 which should be matched against AB_MNO_3, AB_PQR_3 while AB4 should be matched against AB_MNO_4, AB_PQR_4 Rest of the values in these columns in two tables do match. Would highly appreciate if anyone provides recommendations around the same.

回答1:

SELECT * FROM Table1 tl INNER JOIN Table2 t2 
ON (tl.ColA = t2.ColB OR (tl.ColA ='AB3' AND t2.ColB='AB_MNO_3')
OR (tl.ColA ='AB3' AND t2.ColB='AB_PQR_3') OR (tl.ColA ='AB4' AND t2.ColB='AB_MNO_4')
OR (tl.ColA ='AB4' AND t2.ColB='AB_PQR_4'))

回答2:

From your examples : I assume that first two chars of colA and Colb equal AND last char of colA and ColB equal

SELECT * FROM TABLE1 t1 INNER JOIN
TABLE2 t2 ON 
substr(t1.ColA,0,2) =  substr(t2.ColB,0,2) 
AND
substr(t1.cola,length(t1.cola),1) = substr(t2.colb,length(t2.colb),1)

来源：https://stackoverflow.com/questions/7970957/oracle-sql-inner-join-based-on-non-matching-values