drop table if exists t; create table t ( iid int ,nid int ,bid binary(3) ,msg varchar(69) ,key (iid) ,key (bid) ) ENGINE=InnoDB; insert into t values (1,1,1,"ichi"),(2,2,2,"ni"),(3,3,3,"san") ,(4,4,4,"si"),(5,5,5,"go"),(6,6,6,"roku") ; な…