SELECT t1.编号, t1.规格, t2.名称FROM (SELECT 编号, 规格A AS 规格, 数量A FROM tabUNION ALLSELECT 编号, 规格B AS 规格, 数量B FROM tabUNION ALLSELECT 编号, 规格C AS 规格, 数量C FROM tab) t1INNER JOIN t2ON t1.编号 = t2.编号 AND t1.规格 = t2.规格
